Recommended Service procedures
Contents
1. NeicoRemy 1G 286 PRODUCT INFORMATION 1 98 FEAVY DUTY BRUSH ALTERNATOR SERVICE MANUAL 1998 Delco Remy International Inc All Rights Reserved FEATURES B High Output Models e 100 to 145 Amps 12 Volt e 50to 70 Amps 24 Volt B Applications e Large and Mid Range On Highway Diesel and Gasoline Engines e Off Highway Agriculture and Construction Handles Heavy Belt Load and Vibrations High Electrical Loads Heavy Duty Design High Output Rectifier Bridge Double Sealed Needle Bearing 25mm Drive End Ball Bearing Swivel Brush Holder Construction 211 3 mm Specifications Maximum Speed Continuous 10 000 rpm Intermittent 12 000 rpm Ambient Temperature Limits Built in Voltage Regulator 34 C to 93 C 30 F to 4200 F Solid State Integrated Circuit Mounting Span Conforms to SAE J180 Flat Temperature Compensated Polarity Negative Ground Low Parasitic Draw Rotation Clockwise or Counterclockwise Low Turn On Speed Weight 6 46 kg 14 2 Ibs Improved RFI Suppression Load Dump Protection 12 Volt Charging System Wiring One Two or Three Wire Design Terminal Boots Prevent Damage Optional R and or T Terminals Steel Tread Integrated Swivel Brush Insert Circuit Assembly Regulator Grease nmm rm MN pi Ra Double Sealed gt 9 Reservoir m o DA Heavy Duty s 17 gt Ball Bearing Heavy Duty Roller Bearing with Lip Seal Rectifier A Adjustable Bridg2. 35 Final Unit Assembly Thru bolts to 5 5 N m 50 Ib in 29 For one wire systems only regulator terminal cover to regulator terminals Remove or Disconnect 30 Remove brush pin to release brushes onto slip rings inside unit Fig 36 m o Pd 95 E D Mif s sa A H 2 BRUSH PIN Y 113 CAPACITOR A R lt p C 1 SRE HOUSING END OF ASSEMBLED UNIT 114 SCREW SELFTAPPING A R MR6035 R1 Figure 36 Removal of Brush Pin PAGE 18 1G 286 4 96 ALTERNATOR BENCHTEST TEST EQUIPMENT NEEDED e Alternator Test Stand 5000 rpm capability e Battery or Battery Set fully charged e Variable Carbon Pile Load Test e Ammeter current capability at least 15 amps higher than alternator rating e Voltmeter e Ohmmeter This bench test procedure is used to verify that the alternator is functioning properly prior to installation on the vehicle This test checks the alternator output in the same manner as the Rated Output Check covered earlier in this procedure If bench test equipment is not available install the alternator on the engine according to manufacturer s instructions and repeat the Rated Output Check to verify alternator operation If bench test equipment is available proceed as follows 1 Mount alternator in suitable test stand according to test stand manufacturer s instructions Test stand must be capable of driving alternator at speeds up to 5000 rpm 2 IMPORTANT Battery or battery set must
3. CONNECTOR 6 BRIDGE ATTACHING SCREWS 7 CAPACITOR ATTACH SCREWS INSULATED 8 CAPACITOR 9 RECTIFIER BRIDGE wardpap AE MR6017 R1 Figure 18 Removing rectifier Bridge 21 SI HEAVY DUTY BRUSH ALTERNATOR 11 12 13 14 Brush holder assembly must be removed to service brushes or regulator Fig 19 Hold brushes in retracted position and insert brush pin to keep brushes in retracted position Remove insulated regulator attaching screw Remove regulator nut and stud connector if used Loosen or remove inside I terminal nut to move T terminal connector if used as necessary for clearance Finally remove brush holder pivot screw Lift brush holder assembly from housing without bending regulator connector from diode trio or I terminal connector Check brushes and leads for excessive wear breakage etc If necessary to replace note routing of lead wires and position of lead clips for later assembly brushes are identical but leads and clips are positioned differently Carefully remove brush pin to release brushes Fig 19 Remove brushes and spacer one at a time placing fingers around springs to prevent loss It may be necessary to spread the brush lead clips slightly to disengage retaining tabs Remove remaining regulator attaching ground screw If previous checks lead to an instruction to replace the regulator replace it If it is not known whether regulator is good use an approved tester for S
4. Optional connections to the 21 SI series include R relay and I indicator light terminals and a ground lead connection to the alternator housing A Relay terminal may be located either counterclockwise from the BAT terminal where an R is molded into the casting or at an opening clockwise from the BAT terminal and labeled RELAY by a permanent adhesive label next to the terminal On a replacement unit there will be a round push on label on the terminal itself This terminal may be used to operate a charge indicator ADLO system 21 SI HEAVY DUTY BRUSH ALTERNATOR tachometer or similar device by providing voltage pulses at about half of system voltage and at a frequency of 6 times the alternator rpm When an T terminal is present it will be located where there is an I molded into the casting clockwise from the BAT terminal An I terminal is connected internally to the field circuit If an indicator light is connected in series with this terminal the light will be on whenever there is a voltage difference between the positive side of the field circuit and the system voltage at other side of the indicator light During normal alternator operation the light will be off since the diode trio output voltage equals the system voltage The R and I terminals are available in either threaded 10 24 or M4 or pin types A threaded 1 4 or 5 16 hole in the slip ring end SRE frame is provided to connect
5. a ground lead if used otherwise the ground path is through the mounting hardware and brackets to the engine Some applications use a debris shield on the outside of the SRE housing of the alternator Such shields are added by the engine manufacturer to reduce the amount of airborne debris that enters the alternator in severe environments A stud mounted in the T terminal hole may be used to attach the debris shield to the alternator The stud is not connected electrically inside the unit OPERATING PRINCIPLES An alternator is a voltage creating machine The voltage regulator limits the maximum voltage that the alternator will produce at the output BAT terminal by controlling the magnetic field present in the rotor The voltage produced allows current to flow to satisfy the electrical loads placed on the system up to a maximum current characteristic of the alternator design Schematic of the alternator circuitry are shown in Figure 7 one wire systems and Figure 8 three wire systems With the alternator rotor turning magnetic fields around the rotor induce voltages in the stator windings The faster the rotor turns the higher the induced voltage will be In a one wire system the voltages at start up are generated by residual magnetism in the rotor In a 3 wire system rotor magnetism is boosted at start up by field current entering through the 1 regulator terminal then flowing through the rotor windings Because of the boosted
6. fasteners use only correct part number or equivalent e Ifcorrect part number is not available use only equal size and strength For alternator internal fasteners refer to Delco Remy America Standard Hardware Fasteners section in Service Parts Catalog e Fasteners that are NOT to be reused will be noted in procedure e Fasteners requiring thread locking compound will be noted in procedure e Use specified torque values when shown Using or replacing fasteners in any other manner could result in part or system damage If diagnosis determines that alternator repair is needed remove alternator from engine according to manufacturer s instructions DISASSEMBLY AND BENCH CHECKS TEST EQUIPMENT NEEDED e Ohmmeter e 110 Volt Test Lamp optional NOTICE On some alternators on certain engine configurations a 1 5uf capacitor DRA 1985444 has been installed to the output terminal and attached witha 3 8 long 10 24 self tapping screw Remove the screw and the capacitor DRA 1985444 before disassembly ALTERNATOR 1 Place alignment mark across slip ring end SRE housing and drive end DE frame for assembly after repair Fig 12 Remove 4 thru bolts Separate DE frame with rotor from SRE housing with stator If necessary carefully pry DE frame from edge of stator with screwdriver Fig 13 After separation place tape over SRE bearing inside unit to prevent dirt from entering during checks 21 SI HEA
7. for use on large and mid range diesel and gasoline engines in over the road service as well as for off road agricultural and construction equipment The 21 SI Alternator may be operated in either clockwise or counterclockwise directions external fan may require changing to reverse rotation at continuous speed of up to 10 000 alternator rpm Intermittent speeds of up to 12 000 alternator rpm are also acceptable The ambient temperature range for proper operation is 34 C to 93 C 30 F to 200 F The solid state integrated circuit voltage regulator built into the 21 SI Alternator limits system voltage by switching the ground circuit for the rotor field on and off When the ground circuit is on field current passes from a diode trio through the rotor via brushes and slip rings on the rotor shaft Nominal regulated voltages of 13 8 14 0 and 14 2 volts are available for 12 volt systems and 27 5 volts for 24 volt systems Various output levels are available For 12 volt systems output ratings range from 65 amperes to 160 amperes For 24 volt systems output ratings are 50 to 70 amperes Refer to Figure 2 for graphs of typical outputs over a range of alternator speeds For output ratings of specific 21 SI models call 1 800 DRA 0222 UU eed Ps Ad 70 AMP 24 VOLT AMPERES Vi ces HA AE o 0 OD 2006 3006 un n iz GENERATOR RPM 21 5411 Figure 2 Typical Output vs Alternator RPM PAGE 2 1G 286 4 96 FEA
8. nut Fig 43 A Tighten M4 TI and R or Relay terminal nuts to 2 0 N m 20 Ib in 10 24 I and R or Relay terminals nuts to 2 0 N m 20 Ib in 11 Terminal caps to I and R or Relay terminals as necessary PAGE 22 1G 286 4 96 1 GROUND LEAD 2 GROUND GRD HOLE 3 GROUND SCREW WITH LOCKWASHER 4 OUTPUT LEAD 5 OUTPUT BAT TERMINAL 6 LOCK WASHER 7 NUT 113 CAPACITOR LEAD MR6043 R1 Figure 44 Installing Ground and Output Leads 12 Ground lead to GRD hole in SRE housing with ground screw lockwasher assembly Fig 44 A Tighten 1 4 Ground screw to 6 N m 55 lb in 5 16 ground screw to 11 N m 100 Ib in 13 Output lead to BAT terminal using lock washer and output terminal nut Fig 44 A Tighten MO output terminal nut to 11 N m 100 Ib in 1 4 output terminal nut to 7 N m 65 lb in 5 16 output terminal nut to 11 N m 100 Ib in 14 For 3 wire systems only regulator connector to regulator terminals Fig 45 15 Negative cable at battery 21 SI HEAVY DUTY BRUSH ALTERNATOR 1 REGULATOR TERMINALS 2 REGULATOR CONNECTOR 3 1 TERMINAL CIRCUIT INDICATOR LIGHT 4 2 TERMINAL CIRCUIT VOLTAGE SENSE Figure 45 Regulator Connector 3 Wire Systems 21 SI ALTERNATOR SPECIFICATIONS The typical 21 SI Alternator rotor field check at 12 volts is 6 7 7 1 current amps and 1 7 1 8 ohms at 80 F The
9. on ammeter without allowing voltage at battery positive terminal to drop below 13 volts 25 volts on 24 volt system Record maximum ampere output With alternator still running at maximum output check and record voltage drop in ground circuit between alternator housing and battery negative terminal Turn carbon pile load off Maximum ampere output should be within 15 amps of output rating stamped next to part number on alternator drive end DE frame or as listed in Specifications section of this manual Voltage drop should be 0 25 volts or less on 12 volt system 0 5 volts or less on 24 volt system If ground circuit voltage drop is over 0 25 volts on 12 volt system 0 5 volts on 24 volt system clean and tighten all ground circuit connections If this does not correct excessive voltage drop check ground circuit cables for improper sizing or high resistance conditions Correct as necessary If within 15 amps of rating alternator is good Look elsewhere for cause of problem If more than 15 amps below rating repair or replace alternator 21 SI HEAVY DUTY BRUSH ALTERNATOR ALTERNATOR UNIT REPAIR CAUTION Failure to disconnect negative cable at battery before removing or attaching alternator BAT terminal lead may result in an injury If a tool is shorted at alternator BAT terminal the tool can quickly heat enough to cause a skin burn NOTICE Always reinstall fasteners at original location If necessary to replace
10. 9 INSIDE I TERM NUT WASHER ASM 10 DIODE TRIO CONN 11 REGULATOR ATTACH SCREW INSULATED MR6029 R1 Figure 30 Regulator Connector 1 Wire System 1 INSIDE BAT TERM NUT WASHER ASM 2 REGULATOR STUD CONN 3 REGULATOR STUD 4 BAT TERMINAL STUD 5 REGULATOR STUD NUT WASHER ASM 1G 286 4 96 PAGE 15 12 Brush assemblies with springs and spacer to brush holder Fig 28 Brushes are identical but leads and contact clips are positioned differently Pin brushes in retracted position Install or Connect 13 With brushes pinned in retracted position Fig 29 brush holder assembly to mounting holes in regulator and SRE housing Install brush holder attaching pivot screw and one insulated regulator attaching screw finger tighten both screws 14 Diode trio onto 3 threaded studs on rectifier bridge assembly Fig 29 Position long connector strap on diode trio over closest mounting hole in brush holder and regulator For 3 wire systems skip to step 18 15 For one wire systems Fig 30 hold outside output terminal and temporarily remove inside output terminal nut Install regulator stud connector to threaded stud and to inside output terminal stud Reinstall output terminal nut washer and install regulator nut washer assembly to threaded stud on regulator finger tighten 16 I terminal if used with outside insulator to SRE housing and hold in place Fig 31 Inside insulator then regulator
11. Disconnect indicator light circuit at alternator If indicator light remains on locate and correct shorted condition between the light and alternator If indicator light goes out diode is shorted in rectifier bridge Replace rectifier bridge as described under Unit Repair SYSTEMS WITHOUT INDICATOR LIGHT OR WITH INDICATOR LIGHT WORKING PROPERLY TEST EQUIPMENT NEEDED e Voltmeter If battery is undercharged indicator light remains on while vehicle is running or system voltmeter shows operating voltage is below acceptable range With engine stopped and all electrical loads turned off use voltmeter to check voltage across battery terminals Record voltage Start engine and run at moderate speed Check voltage across battery terminals with engine running If voltage reading at battery terminals is different from reading showing at system voltmeter if equipped locate and correct cause of incorrect reading If voltage is lower than reading previously recorded with engine stopped there is no alternator output Proceed to section on No Output If voltage is higher than previous reading with engine stopped alternator output is present Proceed to section on Rated Output Check 2 If battery is overcharged as evidenced by excessive water use or electrolyte spewing from battery vents light bulbs or other electrical equipment have shortened life due to suspected high system voltage or system voltmeter reads a
12. ECTIFIER BRIDGE NUTS MR6032 R1 Figure 33 Installing Stator 21 SI HEAVY DUTY BRUSH ALTERNATOR 1G 286 4 96 PAGE 17 A Tighten Rectifier bridge nuts 3 places to 2 5 N m 22 Ib in FINAL UNIT ASSEMBLY E Clean 24 Slip rings on rotor shaft 1f not previously cleaned by spinning rotor while holding 400 grain polishing cloth around slip rings Fig 34 Blow away all copper dust 1 VISE 25 Rotor shaft where it will slip into SRE bearing by E Eo wiping with soft cloth Shaft must be free of dirt and 4 400 GRAIN POLISHING other foreign material CLOTH OVER SLIP RINGS 26 Brushes by wiping with clean soft cloth Contact surfaces of brushes must be free of grease and other contaminants Be sure brushes are pinned in retracted position and that pin extends through SRE housing for ALIGN SCRIBE MARKS removal after unit assembly Remove protective tape from opening in SRE bearing MR6033 R1 Figure 34 Cleaning Slip Rings 27 As required Capacitor with self tapping screw securely into available hole in SRE housing Install or Connect 27 DE frame assembly to SRE frame assembly aligning marks made earlier on SRE housing and DE frame Fig 35 If mark was lost due to part replacement use mark on old part or match mounting lugs to application to determine proper frame orientation 1 DE FRAME ASSEMBLY 28 Thru bolts 4 places 2 SRE HOUSING ASSEMBLY 3 THRU BOLTS 4 REQ D MR6034 R1 A Tighten Figure
13. I type regulators Always check field coil for shorts when replacing regulator Remove protective tape see step 3 and check bearing in SRE housing Bearings are permanently lubricated do not add grease If bearing is dry or damaged replace o NO OF A WNH 1G 286 4 96 PAGE 11 BRUSH 2 PCS BRUSH PIN REGULATOR ATTACH SCREWS INSULATED BRUSH HOLDER PIVOT SCREW INSIDE TERM NUT IP TERM CONN REGULATOR STUD CONN 3 WIRE SPACER BRUSH SPRINGS BRUSH LEAD CLIP 2 PCS BRUSH HOLDER REGULATOR REGULATOR ATTACH SCREW GROUNDED bearing If bearing is being replaced without removing brushes from SRE housing use brush pin to hold brushes in retracted position while bearing is removed To remove bearing use tube slightly smaller than opening in SRE housing and drive bearing through to inside of housing Fig 20 If bearing is not removed place tape back over bearing 1 SRE HOUSING 2 SRE BEARING 3 TUBE 4 HAMMER MR6019 R1 DE FRAME AND COMPONENTS 15 Use ohmmeter to check rotor field resistance Place ohmmeter leads on the two slip rings on the rotor shaft to make this check Fig 21 Refer to Service Specifications at the end of this section for proper value Also use ohmmeter to check for a grounded field by touching one lead to a slip ring and one lead to rotor frame or shaft Reading should be infinite open to show that field is not grounded If field resistance is outside specificatio
14. T terminal For 3 wire systems disconnect the regulator terminal 2 If indicator light does not come on with the key switch connector terminals 1 and 2 and determine which is in the run position with the engine stopped bulb the indicator lamp circuit by locating the terminal that check mode connect to the 1 terminal on the regulator Use fused 5 amp jumper lead to ground indicator lamp circuit to Leave key in run position with engine stopped alternator housing Disconnect indicator light lead from alternator For one wire systems this will be at the T terminal For 3 If indicator light comes on with jumper lead in place wire systems disconnect the regulator terminal replace regulator as described under Unit Repair connector terminals 1 and 2 and determine which is the indicator lamp circuit by locating the terminal that PAGE 6 1G 266 4 96 If indicator light does not come on with jumper lead in place locate and correct open circuit in indicator light circuit between battery and light Circuit fuse may be open With engine running light is being powered by alternator and grounded through other circuits connected in parallel to indicator light circuit Correct as necessary NOTE If 5 amp fuse blows jumper lead has probably been connected to sense circuit instead of indicator light circuit Replace jumper lead fuse and try again If indicator light is on with key switch in off position
15. TURES The 21 SI Heavy Duty Brush Alternator is available in either a 1 wire 2 wire or 3 wire configuration These wire configurations refer to the minimum number of lead wire connections necessary at the alternator for operation Some applications may use additional connections for accessory operation and or an additional ground lead connection The one wire type requires only that the alternator output BAT terminal be connected to the battery positive terminal and that a ground path be provided between the alternator housing and the battery negative terminal refer to Figure 3 R and or I terminal connections are optional and do not affect alternator operation 1 ALTERNATOR 2 OUTPUT TERMINAL 3 BATTERY 4 IGNITION SWITCH 5 SYSTEM LOADS 6 AMMETER IF USED 7 VOLTMETER IF USED MR6003 R1 Figure 3 Basic One Wire System The two wire type requires the BAT terminal connection to battery positive and the ground path to the alternator housing along with an additional connection See Figure 4 This additional lead should initiate at the ignition switch and through an indicator light or 10 50 ohm resistor or diode to prevent alternator feedback and attach to alternator T terminal 4 IGNITION SWITCH 5 SYSTEMS LOADS 1 ALTERNATOR 2 OUTPUT TERMINAL 3 BATTERY Figure 4 Basic Two Wire System The 3 wire type requires the BAT terminal connection to battery positive and the ground path t
16. VY DUTY BRUSH ALTERNATOR 1 SRE HOUSING 2 STATOR 3 DE FRAME 1 THRU BOLTS 4PCS 2 DE FRAME WITH ROTOR 3 SCREWDRIVER 4 SRE HOUSING WITH STATOR Figure 13 Disassembly of Alternator SRE HOUSING AND COMPONENTS 4 Inspect SRE housing assembly for loose connections or other obvious conditions Correct as necessary If none are found proceed with SRE checks 5 Remove 3 rectifier bridge nuts to disconnect stator Lift stator from SRE housing If necessary carefully pry stator away from SRE housing with screwdriver Fig 14 6 Inspect stator winding for a dark burned appearance View winding from inside of unit black paint on outside of windings does not indicate burned windings If all windings are uniform in color and varnish covering is not flaking off proceed with electrical check If some windings are dark and others are light a shorted open or grounded condition is indicated Replace the stator Ts 1G 286 4 06 PAGE 9 enm ASAS i TY x m li Il m ga cr ih H 5 js D Es ON D T L d DEN HE AEE M 1 SRE HOUSING ASSEMBLY 2 SCREWDRIVER 3 STATOR 4 RECTIFIER BRIDGE NUTS 3 PCS MR6013 R1 uM a E mm ti AAA AA AA 2n TET Y TE Wipss S NC H MI PET L 1 5 e as a A n TATOR LEADS TATOR AMINATIONS MR6014 R1 Figure 15 Electrical Check of Stator The stator should also be replaced if the windings are uniformly dark and burned wi
17. and or T terminal 2 places if used inside nuts to 2 5 N m 22 Ib in It may be necessary to hold terminal on outside while tightening 5 Regulator mounting screw grounding to 2 0 N m 20 lb in 6 Insulated regulator attaching screws 2 places to 2 0 N m 20 Ib in 7 Regulator nut if used to 2 5 N m 22 Ib in 8 Brush holder attaching screw pivot to 2 0 N m 20 Ib in Install or Connect 21 Debris shield mounting stud if used with inside washer to I terminal hole in SRE housing Outside washer lockwasher and nut to mounting stud on outside Tighten nut to 5 5 N m 50 Ib in 22 Stator to SRE housing assembly placing 3 phase leads over 3 threaded studs on rectifier bridge Fig 33 Be sure stator is seated in register around edge of SRE housing 23 Rectifier bridge nuts to 3 threaded studs on rectifier bridge Fig 33 21 SI HEAVY DUTY BRUSH ALTERNATOR 1 REGULATOR STUD CONNECTOR IF USED 2 THREADED STUD IF PRESENT 3 MOUNTING HOLE 4 NUT WASHER ASM IF USED 5 REGULATOR ATTACH SCREW INSULATED 6 DIODE TRIO CONN 7 DIODE TRIO MR6030 R 1 Figure 31 Regulator Connector 3 Wire System vy P P T T dg Jm S m rd h T m E o MT 4 E ES Li RC TR UM pin Kerrie E rq AE a tr op E 4 arb nr y E 1 STATOR uu DOO 2 PHASE LEADS EOY S 3 SRE HOUSING ASSEMBLY 4 THREADED STUDS ON RECTIFIER BRIDGE 5 R
18. be fully charged for test results to be valid NOTICE When a 12 volt carbon pile load test is used to diagnose a 24 volt system attach load test only to 12 volt potential in battery set Attaching a 12 volt load test to a 24 volt potential will damage the load test CARBON PILE LOADTEST SWITCH 10 50 OHM RESISTOR OUTPUT LEAD AMMETER BATTERY VOLTMETER 21 SI HEAVY DUTY BRUSH ALTERNATOR With carbon pile load turned off and with battery or battery set fully charged make electrical connections as show in Fig 37 Connect for one wire or 3 wire type as applicable Battery voltage and ground polarity must be same as system in which alternator is used Check and record battery voltage before proceeding with test Turn on 1 terminal circuit switch 3 wire systems only With carbon pile load off start test stand and slowly increase alternator speed to 5000 rpm Observe voltmeter If voltage does not increase but remains at or below previous reading step 2 there is no alternator output Skip to step 5 If voltage increases above 15 volts on 12 volt system or above 31 volts on 24 volt system voltage is uncontrolled Recheck alternator for proper assembly Assure that test tab in D hole is not grounded If alternator has been assembled properly replace regulator as described under Unit Repair and test field coil for shorts or grounds If voltage is proper proceed to next step With alternator ru
19. bove normal range 21 SI HEAVY DUTY BRUSH ALTERNATOR With fully charged battery engine running at moderate speed and all electrical loads off use voltmeter to check voltage at battery terminals If checking a 3 wire system locate sense lead connects to alternator 2 terminal and gently wiggle the connections at both ends while watching the voltage reading For a 12 volt system readings should be stable around 13 5 14 5 volts and in no case go above 15 volts Fora 24 volt system readings should be stable around 27 28 volts and in no case go above 31 volts One wire system If voltage is erratic or goes above 15 volts 31 volts on 24 volt system replace regulator as described under Unit Repair and test field coil for shorts 3 wire system If voltage is erratic or goes above 15 volts 31 volts on 24 volt system during any of these checks check sense lead for continuity and clean and tighten sense lead connections Recheck voltages with engine running If problem persists replace regulator as described under Unit Repair and test field coil for shorts D NO OUTPUT TEST EQUIPMENT NEEDED e Voltmeter e Jumper Lead 18 ga min no fuse Note that 21 SI Alternators must be connected to a battery for the voltage sensing circuit to allow initial turn on refer to section on Features When properly connected and system checks indicate a no output condition use the following steps to determine if the alternator req
20. ck 6 diodes as follows Place negative ohmmeter lead on grounded heat sink Touch positive ohmmeter lead firmly to metal diode clips that surround each of the 3 threaded studs AII 3 readings should be the same and indicate open circuits Switch leads and repeat All 3 new readings should indicate continuity Repeat checks using insulated positive heat sink in place of grounded heat sink With negative ohmmeter lead on insulated heat sink all 3 readings should indicate continuity Switch leads and repeat All 3 new reading should indicate open circuits If all readings are correct the rectifier bridge is good If any reading is wrong an open or shorted diode is indicated and rectifier bridge should be replaced To remove bridge remove inside BAT terminal nut nut and connector from regulator stud inside R relay terminal nut and connector if used two bridge attaching screws and insulated capacitor attaching screw Lift capacitor and rectifier bridge from SRE housing Fig 18 21 SI HEAVY DUTY BRUSH ALTERNATOR LC ACQOAA Sa 1 ATTACH SCREW INSULATED 2 DIODE TRIO 3 REGULATOR STRAP 4 RECTIFIER BRIDGE STRAPS MR6015 R1 1 GROUND HEAT SINK 2 DIODE CLIPS 3 INSULATED HEAT SINK MR6016 R1 Fea a eg N wre Im GQ LAN s EN Le E a ij 1 BAT TERMINAL NUT f 2 REGULATOR NUT 3 REGULATOR STUD CONN 1 WIRE TYPE 4 RELAY TERMINALNUT 5 RELAY TERMINAL
21. e Steel Bushing 21 5408 21 SI HEAVY DUTY BRUSH ALTERNATOR 1G 286 4 96 PAGE 1 PRODUCT INFORMATION AND SERVICE MANUAL 21 SI HEAVY DUTY BRUSH ALTERNATOR CONTENTS TOUCA rales l Pa ICS ga RECO T 8 CAIUS A DR EE ETE 2 SRE Housing and Components 9 Operating Praise 3 DE Frame and Components 11 ATOUDICSBOOLNHIS iaceo toda Sesute Er ta diet retta ROM UU 4 Alternator Assembly m 12 2 AUS SUC S per ia Dad 4 DE Frame and Components sesiones 12 B Systems with Indicator Light 2t 2 SRE Housing and Components 13 C Systems without Indicator Light 6 Final Unit Assembly oeste petrae E ames d res 17 D NO OUO ee aE Risa nd lass m Und 6 Alternator Bench Check sessassii naicrericcicn sido 18 E Rated Output CHECK osssestissnet besides eek ede 7 Alternator Mounting across Receipt eb eund Ice gs 20 Altemator Unit Rp casse RP ont rn 8 Altemator S POCO AMON curia ls 22 Disassembly and Bench Checks 8 NC I ori vee ssa tact tents 23 5 FAN 6 PULLEY 7 MOUNTING LUGS 1 SLIP RING END SRE HOUSING 2 STATOR 3 DRIVE END DE FRAME 4 ADJUSTMENT LUG 21 5409 Figure 1 21 SI Alternator INTRODUCTION The 21 SI Heavy Duty Alternator is a high output integral charging system with built in diode rectifier and voltage regulator producing DC current for battery electrical systems The 21 SI series is designed
22. g Bearing is permanently lubricated Do not attempt to add grease ALTERNATOR ASSEMBLY ASSEMBLY OF DE FRAME AND COMPONENTS Install l DE bearing and bearing retainer plate to DE frame Install 3 attaching screws Fig 22 A Tighten Retainer plate attaching screws to 3 0 N m 26 lb in Rotor shaft into DE bearing Fig 22 Fan pulley shaft nut washer and shaft nut onto rotor shaft Fig 22 Hold shaft with 5 16 hex wrench in end or wrap rotor in shop cloth and tighten in vice just enough to hold while tightening shaft nut Tighten Shaft nut to 100 N m 75 Ib ft ASSEMBLY OF SRE HOUSING AND COMPONENTS 21 SI HEAVY DUTY BRUSH ALTERNATOR SHAFT NUT REMOVAL COMPONENT DISASSEMBLY 1 HEX WRENCH 2 COMMON WRENCH 3 SHAFT NUT 8 ATTACHING SCREWS 9 RETAINER PLATE 10 DE BEARING 11 DE FRAME MR6021 R1 INSTALL BEARING FLUSH WITH EDGE OF HOUSING A 1 SRE HOUSING 2 SRE BEARING 3 TUBE 4 HAMMER MR6022 R1 Figure 23 SRE Bearing Installation 21 SI HEAVY DUTY BRUSH ALTERNATOR 1G 286 4 906 PAGE 13 Install or Connect 4 SRE bearing into SRE housing Fig 23 Use thin wall socket or tube slightly smaller than hole in SRE housing to drive bearing in from outside Position bearing flush with outside lip of SRE housing Cover opening in bearing with piece of tape to prevent dirt from entering during rest of procedure Install or Connect 5 Rectifier bridge assemble to SRE housing In
23. heat sink and into SRE housing finger tighten Inspect de Regulator mounting area for presence of grease or dirt Fig 27 Good electrical contact is necessary in this area E Clean NOTICE Do not immerse or wet regulator with solvent Internal damage to regulator could result Regulator mounting bosses in SRE housing metal base plate and contact rings on regulator by wiping with clean dry cloth Install of Connect 10 Regulator to SRE housing Fig 27 with regulator attaching screw grounding Finger tighten 11 If placing individual brushes proceed to step 12 If installing complete brush holder assembly skip to step 13 21 SI HEAVY DUTY BRUSH ALTERNATOR 5 RECTIFIER BRIDGE ATTACH SCREW GROUNDING 6 CAPACITOR ATTACH SCREW INSULATED MR6025 R1 1 OUTPUT BAT TERMINAL 2 SRE HOUSING 3 INSIDE BAT TERM NUT WASHER ASM 4 CAPACITOR 1 CLEAN AREA 3 SRE HOUSING 4 REGULATOR ATTACH SCREW GROUND 2 REGULATOR MR6026 R1 Figure 27 Installing Regulator 21 SI HEAVY DUTY BRUSH ALTERNATOR 1 BRUSH WITH ARM 2 BRUSH SPRING 3 SPACER 4 BRUSH HOLDER 5 BRUSH CONTACT CLIP 6 BRUSH PIN MR6027 R1 Figure 28 Assembly of Brush Holder 1 BRUSH PIN 2 BRUSH HOLDER ASM 3 REGULATOR 4 SRE HOUSING 5 ATTACHING SCREW PIVOT 6 REGULATOR ATTACH SCREW INSULATED 7 DIODE TRIO 8 RECTIFIER BRIDGE MR6028 6 l TERMIANL 7 INSIDE INSULATOR 8 P TERMINAL CONN
24. indicator light connector over TI terminal stud inside SRE housing Position other end of connector over mounting hole in brush holder Inside terminal nut washer assembly onto terminal stud finger tighten 17 Second insulated regulator attaching screw to mounting hole in brush holder passing through diode trio connector and TI terminal connector if used Fig 30 Finger tighten For 1 wire systems skip to step 20 PAGE 16 1G 286 4 96 18 For some 3 wire systems Fig 31 regulator stud connector onto threaded stud on regulator positioning other end over brush holder mounting hole Regulator nut to threaded stud on regulator finger tighten NOTE Later regulator designs do not have a threaded stud and the connector is not used The earlier and later designs are interchangeable If replacing regulator having stud by new regulator without stud omit connector and nut if replacing regulator that does have stud by regulator having stud add connector and nut 19 Second insulated regulator attaching screw to mounting hole in brush holder passing through diode trio connector and regulator stud connector Finger tighten 20 Secure SRE component fastener in following order Fig 32 A Tighten 1 Inside output terminal nut to 5 5 N m 50 lb in 2 Rectifier bridge attaching screws 2 places to 3 0 N m 25 lb in 3 Insulated capacitor attaching screw to 2 5 N m 22 Ib in 4 R
25. magnetism a 3 wire system will have a lower turn on speed rpm than a comparable one wire system However once turned on the output curves are identical 1G 286 4 96 PAGE 3 pum ccu I I i I LI 1 1 i I 1 h F I l I I 1 l l l 4 1 1 a i 1 REGULATOR 2 ROTOR FIELD 3 BRUSHES 4 STATOR 5 DIODE TRIO 6 RECTIFIER BRIDGE 7 CAPACITOR MR6006 R1 Figure 7 One Wire Alternator Schematic z VOLTAGE SENSE 2 INDICATOR LIGHT gt BAT R RELAY 1 REGULATOR 2 ROTOR FIELD 3 BRUSHES 4 STATOR 5 DIODE TRIO 6 RECTIFIER BRIDGE 7 CAPACITOR MR6007 R1 Figure 8 Three Wire Alternator Schematic As speed and output increase voltage available at the diode trio becomes sufficient to supply field current for normal operation When the output voltage exceeds the battery voltage the alternator begins to drive the system voltage If the wiring system includes an indicator light the presence of system voltage at the diode trio equalizes the voltage on both sides of the indicator light and the light goes out PAGE 4 1G 286 4 96 While the system voltage is below the voltage regulator setting the regulator turns on the field current through the rotor and allows the alternator to produce as much output as possible for the alternator speed rpm temperature and system voltage When the voltage setting is reached the regulator turns the field current off When the field current i
26. mounting to assure that grounding and insulated mounting screws are installed in the proper location If assembly is proper replace regulator as described under Unit Repair If there is some alternator output but it is still more than 15 amps below the cold output specification check the rotor field brushes stator diode trio and rectifier bridge as described under Unit Repair PAGE 20 1G 286 4 96 ALTERNATOR MOUNTING CAUTION Failure to disconnect negative cable at battery before removing or attaching alternator BAT terminal lead may result in an injury If a tool is shorted at alternator BAT terminal the tool can quickly heat enough to cause a skin burn NOTICE Always reinstall fasteners at original location If necessary to replace fasteners use only correct part number or equivalent NOTICE On some engine configurations a 1 5uf capacitor DRA 1985444 must be installed to the alternator at installation e If correct part number is not available use only equal size and strength e Fasteners that are NOT to be reused will be noted in procedure e Fasteners requiring thread locking compound will be noted in procedure e Use specified torque values when shown Using or replacing fasteners in any other manner could result in part or system damage Always follow engine manufacturer s instructions for mounting alternator on engine The following procedure is typical and may not match all steps necessar
27. ndicator lamp circuit in TEST EQUIPMENT NEEDED harness connector to alternator housing e Jumper Lead with 5 Amp Fuse f indicator light comes on with jumper lead in place repair or replace alternator 1 If indicator light is on with engine running If indicator light does not come on with jumper lead in Stop engine Turn key switch to run position Indicator place locate and correct open circuit in indicator light light should be on If not go to step 3 circuit Circuit fuse may be open or light bulb may be burned out Correct as necessary Disconnect indicator light lead at alternator For one wire systems this will be the T terminal connector NOTE If 5 amp fuse blows jumper lead has probably For 3 wire systems disconnect the regulator terminal been connected to sense circuit instead of indicator light connector terminals 1 and 2 circuit Replace jumper lead fuse and try again If indicator light remains on locate and correct shorted 3 If indicator light comes on while engine is running but or grounded condition in indicator light circuit between is not on with engine stopped and key switch in run the light and the alternator position If indicator light goes out light is working properly Leave key in run position with engine stopped Proceed to C for check of system with indicator light Disconnect indicator light lead from alternator For one working properly wire systems this will be at the
28. nning at about 5000 rpm turn on carbon pile load and adjust to obtain maximum alternator output on ammeter without allowing voltage on voltmeter to fall below 13 volts 25 volts on a 24 volt system CIRCUITSTO REGULATORTERMINALS 1 AND 2 USED FOR 3 WIRETYPE ONLY OMIT THESE CIRCUITS FOR 1 WIRE TYPE A A D SHAPED TEST HOLE 2 BAT GRD mes MAKE GROUND CONNECTION AT ALTERNATOR ALTERNATOR MR6036 R1 Figure 37 Alternator Bench Test 21 SI HEAVY DUTY BRUSH ALTERNATOR 1 D SHAPED TEST HOLE IN SRE HOUSING 2 TEST TAB ON BRUSH CLIP INSIDE UNIT 3 SCREWDRIVER TILTED TO TOUCH TEST TAB AND EDGE OF TEST HOLE AT SAME TIME MR6037 R1 Figure 3 Using Test Hole If ammeter reading is within 15 amps of cold output shown under Specification page 22 alternator is good Turn off carbon pile and stop test stand If ammeter reading is more than 15 amps below specification alternator is not operating properly Proceed to step 5 NOTICE Do not insert screwdriver more than 3 4 into test hole during this step The grounding tab on the brush holder assembly is reached at this distance Inserting the screwdriver deeper may result in internal damage to the alternator Test hole is provided in SRE housing to allow direct grounding of rotor field circuit Fig 38 Grounding the brush tab inside this hole bypasses the regulator and turns the alternator on in full field mode If the alternator
29. ns or if field is grounded replace rotor as described in following steps OHMMETER 1 DE FRAME 2 ROTOR FRAME 3 SLIP RINGS 4 ROTOR SHAFT MR6020 R 1 Figure 21 Electrical Check of Rotor PAGE 12 16 17 18 19 20 21 1G 266 4 96 Hold DE frame and spin rotor by hand to see that it spins freely in ball bearing Bearing is permanently lubricated do not add grease If movement is rough or wobbly replace DE bearing as described in following steps Remove shaft nut by placing 5 16 hex wrench in end of shaft to hold while removing nut with common wrench Fig 22 Turn nut counterclockwise to remove If hex wrench is not available wrap rotor in shop cloth and place in vise tightening just enough to hold while removing shaft nut Lift shaft nut washer pulley and fan from shaft Fig 22 Pull rotor from DE bearing Fig 22 If rotor checked good electrically step 15 inspect slip rings If rough or out of round turn in lathe removing only enough material to make rings smooth and round Maximum indicator reading for roundness is 0 05 mm 002 Finish with 400 grain polishing cloth Blow away all copper dust Clean shaft of any erease that may have accumulated copper dust Remove three attaching screws and bearing retainer plate from DE frame Fig 22 Inspect DE bearing If bearing appears dry or if rotor did not turn smoothly when checked during alternator disassembly replace DE bearin
30. o the alternator housing along with two additional connections refer to Figure 5 The first to the regulator 1 terminal is a switched battery positive field current indicator light lead with an overall circuit resistance of 10 to 50 ohms The second to the regulator 2 terminal is a system voltage sense lead for voltage control An R terminal connection is optional and does not affect alternator operation 21 SI HEAVY DUTY BRUSH ALTERNATOR 1 ALTERNATOR 2 OUTPUT TERMINAL 3 BATTERY 4 IGNITION SWITCH 5 SYSTEM LOADS 6 1 TERMINAL CIRCUIT 7 INDICATOR LIGHT 8 2 TERMINAL CIRCUIT MR6004 R1 Figure 5 Basic Three Wire System External connections to the 21 SI Alternator are made to terminals as shown in Figure 6 The BAT terminal may be 1 4 5 16 or M6 metric size depending on the application requirement Connections to terminals 1 and 2 on 3 wire systems are made by installing a special Packard connector with two blade terminal receptacles and latch feature available in wiring package 1870921 THREE WIRE SYSTEM ONE WIRE amp TWO WIRE SYSTEMS 1 OUTPUT TERMINAL 2 THREADED HOLE FOR GROUNDING 3 RELAY TERMINAL STANDARD LOCATION 4 RELAY TERMINAL OPTIONAL LOCATION 3 WIRE SYSTEM 5 TERMINAL 1 INDICATOR LIGHT or RESISTANCE WIRE 3 WIRE SYSTEM 6 TERMINAL 2 VOLTAGE SENSE 3 WIRE SYSTEM 7 INDICATOR LIGHT TERMINAL 1 amp 2 WIRE SYSTEMS MR6005 R 1 Figure 6 21 SI Electrical Terminals
31. output is proper with the brush tab grounded the previous low output is due to conditions within the regulator Because the voltage is not regulated and can exceed 16 volts in full field mode the test hole should be used only for bench test procedures Insert screwdriver straight into test hole in SRE housing to make contact with tab on grounding brush Tilt handle slightly to ground tab to housing at edge of test hole and hold Again adjust carbon pile to obtain maximum output on ammeter without allowing voltage on 1G 286 4 96 PAGE 19 1 TERMINAL COVER 2 REGULATOR TERMINALS 3 CONNECTOR MR6038 R1 Figure 39 Checking 1 Wire Regulator Terminals voltmeter to fall below 13 volts on 12 volt system 25 volts on 24 volt system Record reading then turn off carbon pile and stop test stand If there is still no output refer to Unit Repair and check rotor and brushes for an open circuit Be sure that brushes are assembled properly and in contact with the slip rings Check internal electrical connections to be sure grounding and insulated mounting screws are installed in the proper locations For a one wire system only remove the regulator terminal cover and verify that there is a connector between the two regulator terminals Fig 39 If not replace regulator as described under Unit Repair If the output is now within 15 amps of the cold output specification Page 22 but was not when checked per step 4 check the regulator
32. r tighten Alternator belt to pulley If engine uses automatic belt tensioner idler skip to step 7 NOTICE Do not pry directly against stator or SRE housing to adjust belt tension Force must be applied to DE frame as described Prying only against stator or SRE housing may damage the alternator 21 SI HEAVY DUTY BRUSH ALTERNATOR 1 DE FRAME 2 STATOR 3 SRE HOUSING 4 PRY BAR 5 WOOD BLOCK IF NEEDED 6 TORQUE WRENCH MR6041 R1 1 R OR I TERMINAL THREADED TYPE WITH HEX BASE 2 HOLDING WRENCH 3 TERMINAL LEAD 4 LOCK WASHER 5 NUT 6 TERMINAL CAP MR6042 R 1 Figure 43 Threaded TP and R Terminals 1G 286 4 96 PAGE 21 If belt tension 1s adjusted by forcing alternator against belt use suitable pry bar positioned against DE frame of alternator Fig 42 If DE frame is not accessible place wood block along side of alternator against both DE frame and SRE housing and pry against wood block Adjust Using belt tension gage adjust to engine manufacturer s specification and hold A Tighten 7 Adjusting lug bolt to 88 N m 64 Ib ft 8 Hex mounting bolt nut to 88 N m 65 Ib ft Measure 9 Belt tension to be sure specification is maintained If not repeat tensioning procedure Install or Connect 10 T and or R or Relay terminal connectors if used For threaded terminals with a hex base hold hex portion of terminal as anti turn while tightening
33. r one wire systems with an T terminal the indicator light current at this terminal will establish normal magnetism With engine stopped and key switch on use voltmeter to check for voltage present at this terminal With I terminal connected and indicator lamp on voltage will be less than battery voltage If necessary to disconnect wiring at I terminal to make this check check for battery voltage in harness wire If voltage is present proceed to step 4 If no voltage is present check terminal circuit for cause of voltage loss bulb may be burned out Correct as necessary 4 If no conditions have been found that might prevent the alternator from turning on step 1 2 or 3 remove alternator from engine in accordance with engine manufacturer s instructions and proceed to Unit Repair CARBON PILE LOAD TEST VOLTMETER 1G 286 4 96 PAGE 7 E RATED OUTPUT CHECK TEST EQUIPMENT NEEDED e Voltmeter e Ammeter current capability at least 15 amperes higher than alternator rating e Variable Carbon Pile Load Test CAUTION Failure to disconnect negative battery cable at battery before removing or attaching alternator BAT terminal lead may result in an injury If a tool is shorted at alternator BAT terminal the tool can quickly heat enough to cause a skin burn Referto Fig 11 fortest equipment hookups as described in following steps If inductive pick up clamp on type ammeter is used place cu
34. rotor field check at 24 volts is 2 2 2 5 current amps and 9 5 10 7 ohms at 80 E Cold current output at 80 Fis shown in the following table Alternator Amperes 80 F MoOp 1600 rpm 5000 rpm 65 12V 65A 12V 90A 12V 100A 12V115A 12V 125A 12V 130A 12V 145A 12V 160A 24V 50A 24V 70A Rated at 160A 8300 rpm For further information on rotations and exact specification number on these or other Delco Remy America Products Call 1 800 DRA 0222 21 SI HEAVY DUTY BRUSH ALTERNATOR 1G 286 4 96 PAGE 23 SERVICE PARTS MR6049 R 1 Illus Illus No Name No Name l Housing SRE pp Pulley 2 Bearing SRE 23 Nut Regulator 3 Rotor Assembly 24 Nut Rectifier Bridge 4 Stator Assembly 23 Nut Shaft de Frame DE 26 Screw amp Lockwasher Rectifier Bridge 6 Bearing DE Attaching 7 Rectifier Bridge Assembly 27 Screw Brush Holder Attachment pivot 8 Diode Trio 28 Screw Regulator Attachment ground 9 Regulator 29 Screw Regulator Attachment insulated 10 Terminal Package Output 30 Screw Capacitior Attachment I1 Terminal Package Relay or I 31 Screw Bearing Retainer Plate Attachment 12 Connector Regulator Stud 32 Screw amp Lockwasher SRE Frame Ground 13 Connector Relay Terminal 33 Washer Shaft Nut 14 Capacitor 34 Bolt Thru 15 Brush Holder Assembly 16 Brush and Arm Miscellaneous 17 Retainer Plate DE Nut Debris Shield Mounting Stud 18 Bushing SRE Hinge Washer Debris Shield Mounting St
35. rrent clamp on alternator output lead and skip to step 4 If series ammeter is used disconnect negative battery cable at battery Install ammeter in series with alternator BAT terminal Reconnect negative battery cable at battery NOTICE When a 12 volt carbon pile load test is used to diagnose a 24 volt system attach load test only to 12 volt potential in battery pack Attaching a 12 volt load test to a 24 volt potential will damage the load test AMMETER ALTERNATOR Figure 11 Rated Output Check PAGE 8 1G 266 4 96 With load turned off attach carbon pile load test across battery Attach voltmeter negative to grounded negative battery terminal Leave positive meter lead open for checks at various points Check and record voltage at battery positive terminal For multi battery systems check positive voltage of battery set connected as if in battery charging mode With all system electrical loads off start engine and run at moderate speed rpm Recheck voltage at battery positive terminal Voltage should be higher than previous reading but below 15 volts on 12 volt system 31 volts on 24 volt system If reading is lower than previous reading step 6 refer to section on No Output If reading is higher than 15 volts on 12 volt system 31 volts on 24 volt system refer to section on High Voltage Output Turn carbon pile load on and adjust to obtain maximum alternator output
36. rt life of light bulbs or other electric equipment caused by abnormally high system voltage e System voltmeter readings outside normal range Diagnose system as follows refer to Figures 9 and 10 A ALL CHARGING SYSTEMS TEST EQUIPMENT NEEDED e Belt Tension Gage e Battery State of Charge Indicator 1 Check electrical system wiring and battery terminals for poor connections or other obvious conditions that might result in shorts opens grounds or high resistance Correct as necessary 2 Check alternator drive belt for proper tension Adjust to manufacturer s specifications 3 Check battery for state of charge If low recharge according to manufacturer s specifications and load test to establish serviceability Further diagnostic tests require a known good fully charged battery for accurate results INDICATOR LIGHT INDICATOR LIGHT CIRCUIT SWITCH A i L INDICATOR LIGHT I TERMINAL CONNECTOR DISCONNECTED EB B2 B3 MR6008 R 1 Figure 9 Troubleshooting a One Wire System 21 SI HEAVY DUTY BRUSH ALTERNATOR 1G 286 4 06 PAGE 9 INDICATOR VOLTMETER INDICATOR LIGHT LIGHT CIRCUIT REGULATOR TERMINAL CONNECTOR DISCONNECTED BATTERY ALTERNATOR JUMPER LEAD WITH 5 AMP P VOLTMETER Ea MIA CEDO Figure 10 Troubleshooting a Three Wire System MR6009 R 1 B SYSTEMS WITH INDICATOR LIGHT connects to the 1 terminal on the regulator Use fused 5 amp jumper lead to ground i
37. s turned off the magnetic field in the rotor collapses and the alternator output voltage begins to fall The falling voltage causes the regulator to turn the field current back on and the magnetic field to rebuild This switching action of the regulator continues rapidly keeping the output and system voltage very close to the voltage setting This will continue unless the electrical demands of the system cause the system voltage to fall below the voltage setting Should this happen the regulator will again allow full field current to flow so that the maximum output of the alternator at the given speed temperature and systems voltage is realized One wire systems use system voltage at the alternator to control the output voltage and extra sense wiring is not needed With a 3 wire system the voltage present in the sense lead is used to control the output voltage Using a sense lead makes it possible to sense the system voltage at another location such as at a junction closer to the battery for voltage control TROUBLESHOOTING Trouble in the charging system will normally be indicated by one of the following e Indicator light on with engine running VOLTMETER STEPS i C1 C2 POLARIZING JUMPER LEAD TOUCH BRIEFLY TO R TERMINAL BATTERY JUMPER LEAD WITH 5 AMP FUSE 21 SI HEAVY DUTY BRUSH ALTERNATOR e Indicator light off with key on engine not running e Undercharged or overcharged battery e Sho
38. stall one rectifier bridge attaching screw washer assembly through grounded heat sink into SRE housing Fig 24 1 SRE HOUSING Finger tighten 2 RECTIFIER BRIDGE 3 ATTACHING SCREW Relay R terminal if used to SRE housing and hold in place see Fig 25 Place inside insulating washer over R terminal stud Place relay terminal connector over stud on rectifier bridge and R terminal stud Be sure inside insulating washer is between connector and SRE housing at terminal end Connector must not touch SRE housing Also be sure outside insulator is properly centered in hole so terminal stud cannot touch SRE housing Install inside nut washer assembly onto R terminal stud 1 R TERMINAL 2 INSULATING WASHER 3 SRE HOUSING 4 R TERMINAL CONNECTOR 5 RECITIER BRIDGE STUD 6 INSIDE NUT WASHER ASM MR6024 R 1 Figure 25 Installing Relay Terminal PAGE 14 1G 286 4 96 A Tighten Inside nut washer assembly to 2 5 N m 22 lb in Output BAT terminal to SRE housing being sure to seat square insulator flange in hole then inside output terminal nut washer assembly onto terminal stud Fig 26 Finger tighten Capacitor to holes in end of rectifier bridge assembly Fig 26 Install rectifier bridge attaching screw washer assembly through capacitor connector grounded heat sink and into SRE housing finger tighten Insulated capacitor attaching screw through capacitor connector insulated
39. th the varnish coating flaking off to expose bare wires Perform electrical check on stator Use ohmmeter or 110 volt test lamp Fig 15 There should be no continuity between any of the stator leads and the stator laminations If continuity is present windings are grounded Replace Stator If there is no continuity stator is probably good However there is no service electrical check for shorted or open delta stator windings If all other electrical checks are normal and the alternator did not produce within 15 amps of the rated output a shorted or open stator in indicated and the stator is to be replaced PAGE 10 16286 4 96 8 Remove insulated regulator attaching screw to disconnect diode trio Fig 16 Lift trio from SRE assembly NOTE Wherever Ohmmeter is specified for use when checking diodes the Diode Test Functions setting should be used for Digital Type multimeters 9 Use ohmmeter to check diode trio Fig 16 Place negative ohmmeter lead on regulator strap and use positive ohmmeter lead to check for continuity to each of the three rectifier bridge straps All three readings should indicate continuity Reverse the ohmmeter leads and perform checks again Readings should all indicate open circuits If all readings are proper diode trio is good f any reading is wrong replace diode trio 10 Use ohmmeter to check rectifier bridge Fig 17 Bridge may be checked in place in the SRE frame Che
40. ud inside 19 Cover Regulator Terminal Washer Debris Shield Mounting Stud outside 20 Cap Relay Terminal Lockwasher Debris Shield Mounting Stud 21 Fan Stud Debris Shield Mounting Connector Regulator to I Terminal I Inc d specifications on these and other 1 800 DRA 0222 G gt y CG Icy onog o G o X coz ee um 56 29 i c o E Vo gt c 9 5 Wo co EWS 58 7 c o O 5 Ot gt T on G E 9 EO a O amp O Lo o i co S LE ud lt b e o O te Re mum ab o e nd le LL Ei e 9 x Gd ts S ax i a 2 E ES 38 e D Ae lo mo os rary MT an
41. uires repair For 3 wire systems use voltmeter to check voltages present in harness connector at regulator With connector disconnected and key switch in run position engine not running both terminals 1 and 2 in harness should read battery voltage If OK go to step 4 If not alternator will not turn on Locate and correct cause of voltage loss 2 For one wire systems without an T terminal battery positive voltage at the BAT terminal and residual magnetism in rotor are necessary for alternator to turn on Use voltmeter to verify that battery voltage is present at BAT terminal If not locate and correct cause of voltage loss Residual magnetism in the rotor is sometimes lost during servicing of the alternator If the alternator has no R or RELAY terminal proceed to step 4 If the alternator has an R terminal the rotor can be remagnetized without removing alternator from application To 21 SI HEAVY DUTY BRUSH ALTERNATOR remagnetize rotor make sure the normal connections are made to the alternator BAT terminal and to the ground circuit Disconnect the wiring harness from the R terminal Momentarily connect a jumper lead from battery positive to the alternator R terminal This will cause field current to momentarily flow through the rotor in the proper direction and restore magnetism Reconnect wiring harness to R terminal then recheck alternator for output 3 Fo
42. y for a particular application TEST EQUIPMENT NEEDED e Belt Tension Gage Remove or Disconnect 1 Negative cable at battery Adjust 2 SRE hinge bushing position so that the mounting lugs will fit over the bracket spool Install or Connect 3 Alternator double mounting lugs to mounting bracket on engine Fig 40 Adjust hinge bushing in mounting lug by tapping endways until it just clears the spool on the mounting bracket Install flanged mounting bolt and flanged mounting bolt nut If bolt and or nut are not flanged 1 8 thick hardened steel washers part no 1967343 must be substituted for flanges Fig 41 21 SI HEAVY DUTY BRUSH ALTERNATOR 1 MOUNTING BRACKET ON ENGINE 2 SRE HINGE BUSHING 3 MOUNTING BOLT 4 MOUNTING NUT 5 ADJUSTMENT BRACKET ON ENGINE 6 FLAT WASHER 7 ADJUSTMENT BOLT da CN les ee ee ee me aA 1 5 in 1 8 IN THICK 1 2 13 FLANGED HEX HEAD HARDENED STEEL ADJUSTMENT BOLT FLAT WASHER SAE GRADE 5 OR BETTER 0 55 I D 1 2 O D 6 25 in i 1 2 13 FLANGED HEAD LOCKING NUT 1 2 13 FLANGED HEX HEAD SAE GRADE 5 OR BETTER MOUNTING BOLT SAE GRADE 5 OR BETTER ALL PARTS ZINC OR PHOSPHATE COATED HARDENEED STEEL WASHERS MAY BE SUBSTITUTED FOR FLANGES MR6040 R1 Figure 41 Alternator Mounting Bolts Alternator adjustment lug to adjustment bracket on engine with 1 8 thick hardener steel washer part no 1967343 and flanged adjustment bolt Fig 40 Finge
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