26-SI ALTERNATOR 1G/287 4/96 PAGE 1G-287 PRODUCT INFORMATION 1/98 26 SI HEAVY DUTY BRUSHLESS ALTERNATOR SERVICE MANUAL ©1998 Delco Remy International Inc. All Rights Reserved.
PAGE 1G-287 4/96 26-SI ALTERNATOR FEATURES SPECIFICATIONS: MAXIMUM SPEED: Continuous: 10,000 rpm Intermittent: 12,000 rpm 198.0 mm AMBIENT TEMPERATURE LIMITS: -40°C to +85°C (-40°F to + 185°F) TRANSIENT VOLTAGE LIMITS: 100V - 300 ms (12-volt) 250V - 300 ms (24-volt) POLARITY: Negative Ground 302.5 mm 26-5010 ROTATION: Clockwise or Counterclockwise WEIGHT: 27.6 lbs (12.
26-SI ALTERNATOR 1G/287 PAGE 4/96 1 PRODUCT INFORMATION AND SERVICE MANUAL 26-SI HEAVY DUTY BRUSHLESS ALTERNATOR CONTENTS Introduction ............................................................... 1 Features ..................................................................... 2 Operating Principles .................................................. 3 Troubleshooting ........................................................ 3 A. All Charging Systems .................................... 4 B.
PAGE 2 1G-287 26-SI ALTERNATOR 4/96 FEATURES GROUND The 26-SI alternator is designed for a “one-wire” charging system configuration. “One-wire” refers to the minimum number of lead wire connections necessary at the alternator for operation and requires only that the alternator output terminal be connected to the battery insulated (positive for a negative-ground system) terminal and that a ground path be provided between the alternator housing and the battery ground terminal.
26-SI ALTERNATOR 1G/287 4/96 PAGE 3 be passed through this circuit to aid in alternator turn-on. An “I” terminal is normally a threaded stud type with a 1024 thread. induce voltages in the stator windings. The faster the rotor turns, the higher the induced voltage will be.
PAGE 4 1G-287 26-SI ALTERNATOR 4/96 TROUBLESHOOTING B. SYSTEMS WITH INDICATOR LIGHT TEST EQUIPMENT NEEDED: Trouble in the charging system will normally be indicated by one of the following: • Jumper Lead with 5-Amp Fuse • • • • Indicator light “on” with engine running. Indicator light “off” with key on, engine not running. Undercharged or overcharged battery. Short life of light bulbs or other electric equipment caused by abnormally high system voltage.
26-SI ALTERNATOR - If indicator light does not come on with jumper lead in place, verify that alternator is properly grounded by touching jumper lead to another ground source. If lamp still does not light, locate and correct open circuit in indicator light circuit. Circuit fuse may be open or light bulb may be burned out. Correct as necessary. 3.
PAGE 6 1G-287 26-SI ALTERNATOR 4/96 E. NO OUTPUT TEST EQUIPMENT NEEDED: • Voltmeter • Jumper Lead (18 ga. min; no fuse) Note that 26-SI alternators must be connected to a battery for the voltage sensing circuit to allow initial turn on (refer to section on Features).
26-SI ALTERNATOR 1G/287 CLAMP-ON AMMETER 4/96 PAGE 7 CARBON PILE A F9 F6,F8 BATTERY ALTERNATOR V VOLTMETER F5 26-5017 Figure 9. Rated Output Check 8. Recheck voltage at insulated battery 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.
PAGE 8 1G-287 26-SI ALTERNATOR 4/96 ALTERNATOR UNIT REPAIR 20 CAUTION: Disconnect grounded cable at battery before removing or attaching battery cable at alternator output terminal. Otherwise, a tool shorted to the battery cable at the output terminal can quickly heat enough to cause a skin burn or damage the tool or cable. 47 33 1 32 NOTICE: Always reinstall fasteners at original location. If necessary to replace fasteners, use only correct part number or equivalent.
26-SI ALTERNATOR OHMMETER 1G/287 9 26 35 35 PAGE 4/96 36 9 53 36 37 9 41 54 1 1. HOUSING ASSEMBLY 9. REGULATOR 26. NUT 36. SCREW (2) 37. SCREW 41. WASHER 52. LEAD 53. LEAD 54. PLATE 9. REGULATOR 35. SCREW (GROUND) 36. SCREW (INSUL.) 26-5021 26-5020 Figure 12. Checking Field Coil Resistance FIELD COIL 3. Disconnect 2 field leads from regulator (9) by removing 2 insulated regulator attachment screws (36). (See Fig. 12) Use ohmmeter to check resistance of field coil.
PAGE 10 1G-287 26-SI ALTERNATOR 4/96 A 25. NUT (3) E OHMMETER G 15 OHMMETER D C 25 F B 13. DIODE STUD PACKAGE 15. DIODE TRIO ASSEMBLY 13 STATOR PHASE LEAD CONNECTION 26-5023 26-5024 Figure 15. Electrical Check of Diode Trio Assembly 6. Use ohmmeter or diode check function on multimeter to check diode trio (15). (See Fig. 15) Place negative ohmmeter lead on regulator lead (A) and use positive ohmmeter lead to check for continuity to each of the three phase leads (B, C, D).
26-SI ALTERNATOR 1G/287 4/96 PAGE 11 RECTIFIER DIODES 31 39 8. Disconnect the 6 diode leads from the 3 diode junction studs by removing nuts. (See Fig. 17) Find the three output side diodes (11), which are installed in the heat sink (12). These diodes will be identical in polarity and will commonly have the same color of insulation on the diode lead wire. Use the ohmmeter or (for digital meters) the diode check function of the multimeter to check the diodes.
PAGE 12 1G-287 26-SI ALTERNATOR 4/96 31 39 25 1. HOUSING ASSEMBLY 10. IN FRAME DIODE (3) 11 10 12 51 1 13 10. HEAT SINK DIODE (3) 11. HEAT SINK DIODE (3) 12. HEAT SINK 13. STUD PACKAGE (3) 25. NUT (3) 31. SCREW (4) 39. WASHER (4) 50. INSULATION 51. INSULATOR (4) 10 49 26-5029 26-5028 Figure 20. Removing Heat Sink Diodes 11. NOTICE: Do not hit diodes or diode mountings with a hammer or other tool. The shock of such an impact can damage the diode or other diodes in the same mounting.
26-SI ALTERNATOR 1G/287 4/96 PAGE 13 29 1. 8. 29. 49. 1 HOUSING ASSEMBLY FIELD COIL ASSEMBLY SCREW (3) GROMMET 1 5 6 1. HOUSING ASSEMBLY 5. STATOR 6. DRIVE FRAME ASSEMBLY 43. THRU-BOLTS (4) 8 49 43 26-5031 26-5033 Figure 23. Separating Housings Figure 25. Removing Field Coil housing (1) apart carefully. Guide stator leads and grommet (48) through hole as stator is pulled from housing. It may be necessary to push on grommet with a blunt instrument to unseat it from the housing. (See Fig.
PAGE 14 1G-287 26-SI ALTERNATOR 4/96 17. To replace rotor (4) or drive end bearing (7), (See Fig. 27) remove 4 bearing retainer attachment screws (28) from outside of housing (1). Lift rotor with bearing from housing, then pull bearing off of rotor shaft. If inside collar (22) appears rough or damaged, pull collar from shaft. 4. 6. 7. 21. 22. 28. ROTOR ASSEMBLY DRIVER FRAME BEARING RETAINER COLLAR SCREWS (4) 18.
26-SI ALTERNATOR 1G/287 4/96 PAGE 15 ALTERNATOR ASSEMBLY 7 21 ASSEMBLY OF DE FRAME AND ROTOR 22 4 INSTALL OR CONNECT 1. Press inner race for rectifier end bearing (3) onto short end of rotor shaft. Stop when race is 3.7 mm (.15 in.) above end of shaft. (See Fig. 29) 2. Press inside collar (22) onto rotor shaft until collar is against shoulder on rotor (4). (See Fig. 29) Place retainer plate (21) onto collar (flanged side of retainer will face away from rotor, toward bearing).
PAGE 16 1G-287 26-SI ALTERNATOR 4/96 1. RECTIFIER END HOUSING 2. OUTER BEARING RACE 3. INNER BEARING RACE 4. ROTOR ASSEMBLY 55. PLUG 1 1 44 2 INSTALL FLUSH WITH INSIDE OF LUG 1. 44. HOUSING ASSEMBLY BUSHING 55 26-5036 3 Figure 31. Installing Slip Bushing 2 Lightly lubricate outside surface of hinge bushing (44). Press hinge bushing into hole in lug on rectifier end housing (1). Install bushing flush with inside of lug to allow maximum distance between two hinge lugs for mounting.
26-SI ALTERNATOR 1G/287 31 39 4/96 13 1 1. 14. 13. 16. 17. 31. 39. 50. 51. 17 HOUSING HEAT SINK ASSEMBLEY STUD PACKAGE TERMINAL TERMINAL SCREW WASHER INSULATION INSULATOR 26-5029 1 26-5027 Figure 33. Installing In-Frame Diodes Figure 35. Installing Heat Sink • Position new in-frame diodes (10) to rectifier end housing (1) so that leads will reach the diode junction studs (13). (See Fig. 33) Using suitable diode installation tools, press new diodes into housing.
PAGE 18 1G-287 26-SI ALTERNATOR 4/96 11. Place insulator (17b) on output terminal (17a) and install through hole in housing (1). (See Fig. 36) Install flat insulator washer (17c), aligning flat shoulders on terminal with slot in heat sink to fully seat terminal. Install nut/washer assembly (17d) onto threaded portion of terminal inside housing. Tighten nut to 5 N.m (45 lb. in.). 12. 29 1 TIGHTEN Two previously installed heat sink mounting screws (31) to 3 N.m (26 lb. in.). 13.
26-SI ALTERNATOR 1G/287 FINAL ALTERNATOR ASSEMBLY 15. CLEAN Inner race of rectifier end bearing (on rotor shaft) to prevent contamination of grease. 16. Align mounting lugs and assemble two halves of alternator (See Fig. 39), inserting rectifier end bearing inner race (on rotor shaft) into rectifier end bearing in rectifier housing. Do not fully seat drive end housing at this time. 17. Insert 4 thru-bolts (43) through drive end housing (6) and stator (5) into threaded holes in rectifier housing (1).
PAGE 20 1G-287 26-SI ALTERNATOR 4/96 20. Place clip of red diode trio lead over hole in heat sink, then install insulator (51), flat washer (39), and heat sink attachment screw (31). (See Fig. 40) TIGHTEN Heat sink attachment screw to 3 N.m (26 lb. in.). 21. Place “R” or “I” terminal (18) into hole in rectifier housing (1). Place insulating washer and plain washer onto stud inside housing. (See Fig.
26-SI ALTERNATOR 1G/287 PAGE 21 TIGHTEN TIGHTEN 25. 4/96 Regulator and mounting plate screws (holes A, B, C, and D) to 3 N.m (26 lb. in.). Heat sink attachment screw each to 3 N.m (26 lb. in.). and regulator stud nut to 2 N.m (18 lb. in.) 26. Insert regulator lead support (57) into slots in housing (1). (See Fig. 43) Place one end of lead to diode heat sink lead (sense lead) over mounting hole in heat sink. Add insulator (51), flat washer (39), and heat sink attachment screw/washer assembly (31).
PAGE 22 1G-287 26-SI ALTERNATOR 4/96 center hole. Replace gasket with a new one if at all questionable. Wipe edges of rectifier end housing and end cover gasket clean of foreign material. Place gasket and cover (19) onto housing (1) and install 7 rectifier cover attachment screw/washer assemblies (32 & 33). (See Fig. 45) TIGHTEN Rectifier cover attachment screws to 5.3 N.m (47 lb. in.). 30. Install spacer and slinger to DE frame on models so equipped (refer to Service Parts section of this manual).
26-SI ALTERNATOR 1G/287 4/96 PAGE 23 CARBON PILE CLAMP-ON AMMETER E9 E6,E8 ALTERNATOR BATTERY V VOLTMETER 26-5046 Figure 47.
PAGE 24 1G-287 26-SI ALTERNATOR 4/96 - If voltage increases above 15 volts on 12-volt system (or above 31 volts on 24-volt system), voltage is uncontrolled. Turn carbon pile load off and stop test stand. Recheck alternator for proper assembly. If alternator has been assembled properly, replace regulator as described under Unit Repair. Also check field coil for shorts and replace if defective.
26-SI ALTERNATOR 1G/287 1/8 IN. THICK HARDENED STEEL FLAT WASHER 0.55" I.D., 1.2" O.D. SAE GRADE 5 4/96 25 TORQUE WRENCH PRY BAR 1.5 IN. 1/2-13 FLANGE HEX BOLT ADJUSTMENT BOLT SAE GRADE 5 OR BETTER 6.25 IN. 1/2-13 FLANGE HEX BOLT ADJUSTMENT BOLT SAE GRADE 5 OR BETTER PAGE BLOCK 1/2-13 FLANGED HEX HEAD LOCKING NUT SAE GRADE 5 OR BETTER ALL PARTS ZINC OR PHOSPHATE COATED STEEL HARDNED STEEL WASHERS MAY BE SUBSTITUTED FOR FLANGES ALTERNATOR 26-5049 Figure 50.
PAGE 26 1G-287 26-SI ALTERNATOR 4/96 5. Alternator belt to pulley. 6. If engine uses automatic belt tensioner (idler), skip to Step 7. NOTICE: Do not pry directly against rectifier end housing to adjust belt tension. Force must be applied to DE frame as described. Prying only against rectifier end housing may damage alternator. If belt tension is adjusted by forcing alternator against belt, use suitable pry bar positioned against DE frame of alternator. (See Fig.
26-SI ALTERNATOR 1G/287 4/96 PAGE 27 1971105 Chargelead Cable or equivalent and match ridges in cable contact with grooves on alternator terminal to provide anti-turn during installation. TERMINAL NUT WASHER TO BATTERY TIGHTEN MALE OUTPUT TERMINAL Insulated output terminal bolt to 14 N.m (120 lb. in.), or 1/4" output terminal nut to 7 N.m (65 lb. in.). 13. Connect negative cable at battery. 26-SI ALTERNATOR SPECIFICATION The typical 26-SI Alternator rotor field check at 12-volts is 3.0 - 4.
PAGE 28 1G-287 26-SI ALTERNATOR 4/96 SERVICE PARTS Illus. No. Name 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31.
26-SI ALTERNATOR 1G/287 PAGE 4/96 29 34 46 20 52 48 33 32 5 19 29 49 47 8 31 14 35 26 39 36 11 53 25 4 38 37 9 40 51 13 41 25 55 21 12 57 22 10 15 16 7 17 30 24 6 45 50 18 56 1 43 28 44 2 3 23 42 27 26-5054
PAGE 1G-287 26-SI ALTERNATOR 4/96 Delco Remy International, Inc. 2902 Enterprise Drive Anderson, IN 46013 For further information and specifications on these and other Delco Remy Products call: 1-800-DRA-0222 © Copyright DRI, 1G-500 10/97 Delco Remy is a registered trademark licensed by General Motors Corporation.
