Starter Motor: Testing and Inspection
Starter TestNOTE: The air temperature must be between 59 and 100° F (15 and 38° C) before testing.
Recommended Procedure:
- Use a starter system tester.
- Connect and operate the equipment in accordance with manufacturer's instructions.
Alternate Procedure:
- Use the following equipment:
- Ammeter, 0-400 A
- Voltmeter, 0-20 V (accurate within 0.1 Volt) Tachometer, 0-1,200 rpm
- Hook up voltmeter and ammeter as shown.
1. Disconnect the No. 13 (30 A) fuse from the engine compartment fuse/relay box.
2. Check the starter engagement:
Depress the clutch pedal all the way (M/T) or shift to [P] or [N]; position (A/T), and turn the ignition switch to "Start (III)". The starter should crank the engine.
NOTE: On cars equipped with manual transmission, the engine will not crank unless the clutch pedal is fully depressed.
- If the starter still does not crank the engine, check the battery, battery positive cable, ground and the wire connections for looseness or corrosion.
- Test again.
If the starter still does not crank the engine, bypass the ignition switch circuit as follows: Unplug the connector (BLK/WHT wire) from the starter. Connect a jumper wire from the battery positive (+) terminal to the solenoid terminal. The starter should crank the engine.
- If the starter still does not crank the engine, remove the starter and diagnose its internal problems.
- If the starter cranks the engine, check for an open in the BLK/WHT wire and connectors between the starter and ignition switch. Check the ignition switch.
On cars with automatic transmission, check the A/T gear position switch (neutral position switch) and connector.
On cars with manual transmission, check the starter cut relay, clutch interlock switch and connectors.
NOTE: Check the No. 29 (50 A) fuse and the starter cut relay, and inspect the security alarm system.
3. Check for wear or damage:
The starter should crank the engine smoothly and steadily.
If the starter engages, but cranks the engine erratically, remove the starter motor. Inspect the starter, drive gear and flywheel ring gear for damage.
Check the drive gear overrunning clutch for binding or slipping when the armature is rotated with the drive gear held. Replace the gears if damaged.
4. Check cranking voltage and current draw: Voltage should be no less than 8.5 Volts. Current should be no more than 350 amperes.
If voltage is too low, or current draw too high, check for:
- Low battery.
- Open circuit in starter armature commutator segments.
- Starter armature dragging.
- Shorted armature winding.
- Excessive drag in engine.
5. Check cranking rpm:
Engine speed during cranking should be above 100 rpm.
If speed is too low, check for:
- Loose battery or starter terminals.
- Excessively worn starter brushes.
- Open circuit in commutator segments.
- Dirty or damaged helical spline or drive gear.
- Defective drive gear overrunning clutch.
6. Check the starter disengagement:
Depress the clutch pedal all the way (M/T) or shift to or P position N, turn the ignition switch to "Start (III)", and release to ON (II).
The starter drive gear should disengage from the flywheel ring gear.
If the drive gear hangs up on the flywheel ring gear, check:
- Solenoid plunger and switch for malfunction.
- Drive gear assembly for dirt or damaged overrunning clutch.
Starter Cut Relay Test
1. Remove the glove box.
2. Disconnect the 4P connector from the starter cut relay.
(Wire colors of 4P connector: BLK/GRN, BLK/WHT, BLK/BLU and BLK/WHT)
Starter Cut Relay Test:
3. Check continuity at the relay terminals.
- There should be continuity between the C and D terminals.
- There should be continuity between the A and B terminals when power and ground are connected to the C and D terminals.
- There should be no continuity between the A and B terminals when power is disconnected.
Clutch Interlock Switch Test (M/T)
1. Remove the dashboard lower cover, then disconnect the 2P connector from the switch.
Clutch Interlock Switch Test (M/T):
2. Check for continuity between the terminals according to the table.
3. If necessary, replace the switch or adjust the switch position.
Starter Solenoid Test
Starter Solenoid Test:
1. Check the hold-in coil for continuity between the S terminal and the armature housing (ground). The coil is OK if there is continuity.
2. Check the pull-in coil for continuity between the S and M terminals.
The coil is OK if there is continuity.
Starter Brush Holder Test
Starter Brush Holder Test:
1. Check that there is no continuity between the (+) and (-) brush holders.
If continuity exists, replace the brush holder assembly.
2. Insert the brush into the brush holder, and bring the brush into contact with the commutator, then attach a spring scale to the spring. Measure the spring tension at the moment the spring lifts off the brush.
Starter Brush Holder Test:
Spring Tension:
18.0-24.0 N (1.80-2.40 kg, 4.0-5.3 lbs)
Starter Brush Inspection
Measure the brush length. If not within the service limit, replace the armature housing and brush holder assembly.
Starter Brush Inspection:
Brush Length
Standard (New): 15.0-15.5 mm (0.591-0.610 in)
Service Unit: 10.0 mm (0.394 in)
NOTE: To seat new brushes after installing them in their holders, slip a strip of #500 or #600 sandpaper, with the grit side up, over the commutator, and smoothly rotate the armature. The contact surface of the brushes will be sanded to the same contour as the commutator.
Armature Inspection and Test
Armature Inspection And Test:
1. Inspect the armature for wear or damage due to contact with the field coil magnets.
2. A dirty or burnt commutator surface may be resurfaced with emery cloth or a lathe within the following specifications.
Armature Inspection And Test:
Commutator Diameter
Standard (New): 29.9-30.0 mm (1.177-1.181 in)
Service Limit: 29.0 mm (1.142 in)
Armature Inspection And Test:
Commutator Runout
Standard (New): 0-0.02 mm (0-0.0008 in)
Service Limit: 0.05 mm (0.002 in)
3. If the commutator runout and diameter are within limits, check the commutator for damage or for carbon dust or brass chips between the segments.
4. If the surface is dirty, recondition it with a #500 or #600 sandpaper. Then, check mica depth. If necessary, undercut mica with a hacksaw blade to achieve proper depth.
Armature Inspection And Test:
Commutator Mica Depth
Standard (New): 0.5-0.8 mm (0.02-0.03 in)
Service Limit: 0.2 mm (0.008 in)
Armature Inspection And Test:
5. Check for continuity between the segments of the commutator. If an open circuit exists between any segments, replace the armature.
Armature Inspection And Test:
6. Place the armature on an armature tester. Hold a hacksaw blade on the armature core.
If the blade is attracted to the core or vibrates while the core is turned, the armature is shorted. Replace the armature.
Armature Inspection And Test:
7. With an ohmmeter, check that no continuity exists between the commutator and armature coil core, and between the commutator and armature shaft. If continuity exists, replace the armature.
Solenoid Plunger Inspection
Solenoid Plunger Inspection:
Check the contact points and face of the starter solenoid plunger for burning, pitting or any other defects. If surfaces are rough, recondition them with a strip of #500 or #600 sandpaper.
Starter Field Winding Test
1. Check for continuity between the brushes. If there's no continuity, replace the armature housing.
Starter Field Winding Test:
2. Check for continuity between each brush and the armature housing (ground).
If continuity exists, replace the armature housing.
Overrunning Clutch Inspection
1. Check if the overrunning clutch moves along the shaft freely. If not, replace the overrunning clutch assembly.
Overrunning Clutch Inspection:
2. Check if the overrunning clutch locks in one direction and rotates smoothly in reverse. If it does not lock in either direction or it locks in both directions, replace the overrunning clutch assembly.
3. Check if the starter drive gear is worn or damaged. If the gear is worn or damaged, replace the overrunning clutch assembly; the gear is not available separately.
NOTE: Check the condition of the flywheel or torque converter ring gear if the starter drive gear teeth are damaged.