Starting System Chevrolet Blazer S15

DESCRIPTION

The Delco-Remy starter is part of the cranking circuit, which also consists of the battery, ignition switch and related wiring. (Scheme 1) When the ignition switch is turned to the START position, the starter solenoid windings are energized. This causes the solenoid plunger to move the shift lever, which engages the pinion with the engine flywheel ring gear. The movement of the plunger also closes the main solenoid contacts, applying battery voltage to the starter motor.

When the engine starts, the pinion will overrun, protecting the armature from excessive speed and the flywheel from damage. When the ignition switch is released, the plunger return spring disengages the pinion.

On starters with the SD designation, the pinion is driven directly by the armature shaft. Wound field coils energize pole pieces that are arranged around the armature. These are used on gasoline engines. Starters designated with PG have a pinion that is driven by a gear reduction system. These starters are used on diesel or large displacement gasoline engines. The PG260 starter should not be dissembled for any reason and is serviceable only by complete replacement. The 28MT starter is used on diesel truck engines and is a gear reduction starter with an overrunning roller type clutch and enclosed shift lever.

Scheme 1

STARTER NOISE

1. A high-pitched whine, heard while cranking (before engine starts), indicates excessive distance between starter pinion and flywheel. If high-pitched whine is heard after engine starts and key is released, distance between starter pinion and flywheel is too small. Pinion-to-flywheel clearance should measure.020" (0.5 mm). (Scheme 2)
2. If loud, siren-like "whoop" sound is heard after the engine starts, drive assembly is likely defective. If "rumble", "growl" or "knock" is present as starter is coasting to a stop after starting engine, starter armature is bent or unbalanced. NOTE: Check flywheel ring gear for damage.
3. If diagnosis indicates pinion should be closer to flywheel, ensure proper starter motor was installed. During initial starter motor installation, shim(s) are not used. If shim(s) are present, remove as necessary.
4. If diagnosis indicates pinion should be moved away from flywheel, add one shim. Consult manufacturer for required shim size. If condition is not corrected, another shim may be added. See «STARTER»(/chevrolet/blazer/s15-1994-1998/remont/starter/#starting-system) under REMOVAL & INSTALLATION.

Scheme 2

Note. For additional trouble shooting information, refer to the TROUBLE SHOOTING - BASIC PROCEDURES article in the GENERAL TROUBLE SHOOTING section.

CRANKING TEST

Note. The following tests assume that engine and battery are operating normally and that there are no engine problems that would cause a no-start condition.

Note. Anti-Theft and PASS-Key II systems interact with cranking system through a starter enable relay or theft deterrent relay. On models with Anti-Theft system and/or PASS-Key II system, ensure both systems and related controls are operating properly. On models with Anti-Theft system, an unauthorized entry will cancel starter enable operation. On all models, ensure no diagnostic trouble codes are present.

Slow Or No Crank After Extended Periods Of Vehicle Non-Use

There may be a parasitic load on electrical system. See the PARASITIC LOAD EXPLANATION & TEST PROCEDURES article in GENERAL INFORMATION.

Engine Does Not Crank, Starter Solenoid Does Not Click

1. Place gear selector in Park (A/T), or depress clutch pedal (M/T). Connect test light between starter solenoid terminal "S" (Purple wire) and ground. Turn ignition switch to START position and observe test light. (Scheme 2) See WIRING DIAGRAM. If test light illuminates, go to next step. If test light does not illuminate, go to step 3) (M/T) or step 5) (A/T).
2. Connect test light between starter solenoid terminal "S" (Purple wire) and starter mounting bolts. Turn ignition switch to START position and observe test light. If test light does not illuminate or is dim, clean starter, starter mounting bolts and mounting surface. If test light illuminates, replace starter solenoid.
3. On M/T models, disconnect clutch start switch connector. Turn ignition switch to START position. Using DVOM, measure voltage between clutch start switch connector terminal "C" (Yellow wire) and ground. If voltage is not present, go to step 7). If battery voltage is present, go to next step.
4. Depress clutch pedal, place gear selector in Neutral and apply parking brake. Connect a fused jumper wire between terminals of clutch start switch connector. Turn ignition switch to START position. If engine cranks, adjust or replace clutch start switch. If engine does not crank, repair open in Purple wire circuit between clutch start switch and starter relay.
5. On A/T models, disconnect park/neutral position switch C1 connector. Turn ignition switch to START position. Using DVOM, measure voltage between park/neutral position switch connector terminal "G" (Yellow wire) and ground. If voltage is not present, go to step 7). If battery voltage is present, go to next step.
6. Connect a fused jumper wire between park/neutral position switch connector terminals "G" (Yellow wire) and "E" (Purple wire). Turn ignition switch to START position. If engine cranks, replace park/neutral position switch. If engine does not crank, repair open in Purple wire circuit between park/neutral position switch and starter relay.
7. On A/T and M/T models, turn ignition switch to START position. Using DVOM, measure voltage between Yellow terminal of ignition switch connector and ground. If voltage is not present, go to next step. If battery voltage is present, repair open in Yellow wire circuit between ignition switch and clutch start switch (M/T) or park/neutral position switch (A/T).
8. Turn ignition switch to START position. Using DVOM, measure voltage between Red wire terminal of ignition switch connector and ground. If battery voltage is present, replace ignition switch. If voltage is not present, go to next step.
9. Using DVOM, measure voltage between Red wire terminal of fusible link "B" at battery junction block and ground. If battery voltage is present, repair open in fusible link "B" or Red wire circuit between fusible link "B" and ignition switch. If voltage is not present, go to next step.
10. Using DVOM, measure voltage between Red wire terminal of alternator BAT terminal and ground. If battery voltage is present, repair open in fusible link "F" or Red wire circuit between fusible link "F" and battery junction block. If voltage is not present, repair open in fusible link "G" or Red wire circuit between fusible link "G" and alternator.

Solenoid Clicks, Engine Does Not Crank

1. Using DVOM, measure voltage between battery positive terminal and battery negative terminal while cranking engine for at least 15 seconds. If voltage is greater than 9.5 volts, go to next step. If voltage is less than 9.5, load test battery. Replace battery as necessary. If battery load test is okay, repair starter motor.
2. Using DVOM, measure voltage between battery negative terminal and engine block. Turn ignition switch to START position. If voltage is less than 0.5 volt, go to next step. If voltage is greater than 0.5 volt, replace battery negative cable.
3. Using DVOM, measure voltage between starter solenoid terminal "B" (Black wire) and battery positive terminal. Turn ignition switch to START position. If voltage is less than 0.5 volt, repair starter motor. If voltage is greater than 0.5 volt, replace battery positive cable.

PRELIMINARY TESTS

Remove starter from vehicle. See STARTER under REMOVAL & INSTALLATION. Check starter for damage such as broken or stripped electrical terminals, broken or cracked drive end housing, etc. If no obvious damage is found, perform starter no-load test and pinion clearance check before disassembling starter motor.

Note. On PG260 and PG260M starter motors, starter is serviced as an assembly. If test values do not meet specifications, replace starter and solenoid as an assembly.

SOLENOID WINDINGS TESTS

Note. To prevent overheating, DO NOT allow solenoid pull-in current to flow for more than 15 seconds.

Note. Current flow will decrease as windings heat up.

Hold-In Windings Test

1. If solenoid is not removed from starter motor assembly, disconnect field lead from terminal "M" on solenoid and insulate field lead from solenoid motor terminal. Connect an ammeter and switch in series with 12-volt battery and starter solenoid terminal "S" as illustrated. (Scheme 3) Connect a voltmeter between solenoid terminal "S" and ground. Connect a carbon pile across battery.
2. Turn switch on and quickly adjust carbon pile load until voltage reads as specified. See «PULL-IN WINDINGS SPECIFICATIONS»(/chevrolet/blazer/s15-1994-1998/remont/starter/#starting-system) table. Check ammeter reading. Turn off carbon pile and open switch. If amperage reading is not 10-20 amps, replace starter solenoid.

Pull-In Windings Test

Connect test equipment as in hold-in windings test. See HOLD-IN WINDINGS TEST above. (Scheme 3) Ground starter solenoid terminal "M". Turn switch on and quickly adjust carbon pile load until voltage reads as specified. See PULL-IN WINDINGS SPECIFICATIONS table. Check ammeter reading. Turn off carbon pile and open switch. See the PULL-IN WINDINGS SPECIFICATIONS table. If ammeter reading is not as specified, replace starter solenoid.

Scheme 3

STARTER NO-LOAD TEST

1. Secure starter in vise. Turn carbon pile off and open switch. Connect test equipment to starter as illustrated. (Scheme 4) Turn switch on and adjust carbon pile until voltage reads as specified. See the «STARTER NO-LOAD TEST SPECIFICATIONS»(/chevrolet/blazer/s15-1994-1998/remont/starter/#starting-system) table. Check ammeter reading and pinion speed on RPM indicator. Turn off carbon pile and open switch. Compare RPM and amperage readings with specifications. See the «STARTER NO-LOAD TEST SPECIFICATIONS»(/chevrolet/blazer/s15-1994-1998/remont/starter/#starting-system) table. CAUTION: DO NOT apply more voltage than specified. Excessive voltage may cause armature to throw windings due to excessive speed.
2. If amperage and RPM readings are as specified, starter motor is okay. If test indicates low free speed and/or high current draw, unit may have tight, dirty or worn bearings or bushings, shorted or grounded armature, or a grounded field.
3. High current draw with pinion moving into cranking position but no pinion rotation indicates a direct ground in field, or frozen bearings or bushings. No pinion movement and a normal current reading indicates plunger is unable to move into solenoid or drive is unable to move on armature shaft. No pinion movement and very low or no current draw indicates an open or ground in solenoid windings.
4. Pinion moving into cranking position but not turning and very low current draw indicates an open in field circuit or armature windings, or no current flow between solenoid battery and motor field terminals while motor is engaged. Connect a jumper wire between solenoid battery and motor field terminal "M". If motor now turns at specified RPM, replace solenoid.
5. Low no-load and low current draw indicates high internal resistance due to poor brush lead connections; a dirty commutator; an open in armature windings; broken, worn or weak brush springs; or worn, damaged or dirty brushes. High no-load speed and high current draw indicates shorted field coils or shorted armature windings.

Scheme 4

ARMATURE TEST

1. Inspect solder joints between armature windings and commutator bars. If any have come loose, replace armature. If commutator is rough or damaged, replace armature. DO NOT turn commutator in lathe or undercut spaces between bars. If commutator is dirty, clean with 400 grit emery cloth and blow away any copper dust.
2. Using growler, check armature for shorts. Hold a flat steel strip on armature parallel to armature core or shaft. Rotate armature in growler. Steel strip will vibrate on area of short circuit.
3. Using self-powered test light, place one lead on armature shaft and other lead on commutator. Test light should not illuminate. If test light illuminates, armature is shorted or grounded and must be replaced.
4. If no-load test indicated armature may be rubbing against inside of frame and field assembly, inspect outside of armature for signs of rubbing. If armature is scored only on one side of laminations, armature shaft may be bent and armature should be replaced. If scoring is all around armature laminations, check frame and field assembly for an out-of-position pole or for a foreign object lodged inside. Repair or replace frame and field assembly.

FIELD COIL OPEN TEST

Remove armature from frame and field assembly. Using self-powered test light, place one lead on field lead connection and other lead on one insulated brush. (Scheme 5) Test light should illuminate. If test light does not illuminate, field coil is open. Repair or replace field and frame assembly. Repeat test for each insulated brush.

Scheme 5

FIELD COIL GROUND TEST

Remove armature from field and frame assembly. On starters with shunt lead, separate field and shunt lead connections during test. Ensure field lead connection is NOT touching ground during test. Using self-powered test light, place one lead on grounded brush holder and other lead on one insulated brush. (Scheme 6) Test light should not illuminate. If test light illuminates, field coil is grounded. Repair or replace field and frame assembly. Repeat test for each insulated brush.

Scheme 6

BRUSHES, SPRINGS & HOLDERS CHECK

Replace brushes if worn to 1/2 of original length, oil-soaked or pitted. Check brush spring tension and replace springs if weak, discolored or distorted. Ensure brush holders are clean and brushes are not binding in holders. Ensure full surface of brush contacts commutator for proper performance.

DRIVE ASSEMBLY CHECK

1. Check pinion teeth for chips, cracks or excessive wear. If pinion teeth are damaged, replace drive assembly. Also check flywheel for damage. Check drive assembly for slipping before disassembly from armature. With drive assembly attached to armature, cover armature with shop towels and secure in a vise.
2. Using a 12-point socket and a torque wrench, turn pinion counterclockwise. Pinion should lock and withstand a torque of 50 ft. lbs. (68 N.m) without slipping. If pinion slips before 50 ft. lbs. (68 N.m) is reached, replace drive assembly.
3. Using a 12-point socket and a torque wrench, turn pinion clockwise. Pinion should turn freely in overrunning direction (clockwise) only. If pinion does not turn freely in clockwise direction, replace drive assembly.

PINION CLEARANCE CHECK

1. Secure starter motor in vise with opening in housing accessible for measurement. Disconnect field lead at solenoid terminal "M" and insulate from solenoid field terminal "M". Connect battery negative terminal lead to starter frame. Connect 12 volts to starter solenoid terminal "S". Momentarily touch jumper lead from starter solenoid terminal "M" to starter frame, shifting pinion into cranking position.
2. Push pinion as far as possible away from retainer. Using a feeler gauge, ensure there is.010-.160" (.25-4.06 mm) clearance between pinion and retainer. (Scheme 7)

Note. Pinion clearance is not adjustable. If clearance is not within specification, disassemble and check starter motor for worn or damaged components.

Scheme 7

REMOVAL & INSTALLATION

STARTER

Note. Vehicles are designed for starter mounting without shims. A single shim or double shims may have been added to correct a noise or engagement condition. When installing starter any previously installed shims should be replaced in original location to ensure proper pinion to flywheel clearance.

Removal & Installation (Bravada, Jimmy, "S/T" Series Blazer)

1. Disconnect negative battery cable. Raise and support vehicle. Remove brush end mounting bracket (if equipped). Remove starter solenoid terminal "S" nut and battery cable nut. Separate wiring from starter.
2. Remove skid plate (if equipped). Remove 2 brakeline-to-crossmember brackets. Remove 6 crossmember bolts and remove crossmember. Remove transmission cooler line-to-flywheel housing bracket. Remove brace rod-to-flywheel housing. Remove lower flywheel housing cover (if necessary).
3. Remove starter mounting bolts. Note location and number of shims for reassembly. Remove starter. To install, reverse removal procedure. Ensure shims are installed in original location. Tighten starter mounting bolts to specification. See «TORQUE SPECIFICATIONS»(/chevrolet/blazer/s15-1994-1998/remont/starter/#starting-system__torque-specifications) .

Removal (2WD Sonoma & "S" Series Pickup)

1. Disconnect negative battery cable. Raise and support vehicle. Remove front exhaust pipe. On 2.2L, remove brace rod from front of engine to bellhousing. On all models, remove starter solenoid terminal "S" nut and battery cable nut. Separate wiring from starter.
2. On 2.2L, remove starter mounting bracket-to-engine bolts. On all models, remove starter mounting bolts. Note location and number of shims for reassembly. Remove starter. On 2.2L, remove brush end bracket from starter. On 4.3L, remove shield from starter.

Installation

To install, reverse removal procedure. Ensure shims are installed in original location. Tighten starter mounting bolts to specification. See TORQUE SPECIFICATIONS .

Removal & Installation (4WD Sonoma & "T" Series Pickup)

1. Disconnect negative battery cable. Remove engine mounts. Raise and support vehicle. Support transmission and remove transmission mounts. Remove starter mounting bolts and rotate starter. Remove starter solenoid terminal "S" nut and battery cable nut. Separate wiring from starter.
2. Note location and number of shims for reassembly. Remove starter. Remove shield from starter. To install, reverse removal procedure. Ensure shims are installed in original location. Tighten starter mounting bolts to specification. See «TORQUE SPECIFICATIONS»(/chevrolet/blazer/s15-1994-1998/remont/starter/#starting-system__torque-specifications) .

Starter motors do not require lubrication, except during overhaul. Roll-type overrunning clutch requires no lubrication. Drive assembly, however, should be wiped clean and lubricated with silicon grease on shaft, underneath overrunning clutch assembly. (Scheme 8)

Note. On PG260 and PG260M starter motors, starter and solenoid are not overhauled and are replaced as a complete assembly.

Scheme 8

Starter System Schematic (Bravada, Jimmy, Sonoma, & "S/T" Blazer & Pickup). Scheme 9

STARTER SPECIFICATIONS

PULL-IN WINDINGS SPECIFICATIONS

STARTER NO-LOAD TEST SPECIFICATIONS

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

See also:
• TROUBLE SHOOTING - BASIC PROCEDURES
• PARASITIC LOAD EXPLANATION & TEST PROCEDURES
• COMPUTER RELEARN PROCEDURES
• STARTER
• TORQUE SPECIFICATIONS