Starters: Diagnosis Lexus SC II

TROUBLE SHOOTING

Note. See STARTER - GENERAL TROUBLE SHOOTING article in GENERAL INFORMATION.

STARTER RELAY TEST

Remove starter relay. See COMPONENT LOCATIONS. Check for continuity between starter relay terminals No. 1 and 2. (Scheme 1) Continuity should exist. If continuity does not exist, replace relay. Check for continuity between starter relay terminals No. 3 and 5. Continuity should not exist. If continuity exists, replace relay. Apply battery voltage across starter relay terminals No. 1 and 2. Check for continuity between starter relay terminals No. 3 and 5. Continuity should exist. If continuity does not exist, replace relay.

Scheme 1

SOLENOID TEST

1. Disconnect starter field coil lead from terminal "C". Connect battery to starter solenoid as indicated. (Scheme 2) Perform STEP 1. Clutch pinion gear should move outward. If clutch pinion gear does not move outward, replace starter solenoid. If clutch pinion gear moves outward, go to next step.
2. Leave battery connected. Disconnect jumper lead from terminal "C". Perform STEP 2. Clutch pinion gear should remain in outward position. If clutch pinion gear does not remain in outward position, replace starter solenoid. If clutch pinion gear remains in outward position, go to next step.
3. Disconnect jumper lead from starter housing. Perform STEP 3. Clutch pinion gear should move inward. If clutch pinion gear does not move inward, replace starter solenoid. If clutch pinion gear moves inward, starter solenoid is okay.

Scheme 2

NO-LOAD TEST

Connect battery and ammeter to starter as indicated. (Scheme 2) Perform STEP 4. Starter armature should rotate smoothly and steadily with pinion gear moving out. Amperage draw should be 100-Amps or less within 11.5 volts.

ARMATURE TEST

1. Using ohmmeter, check for continuity between all segments of commutator. If continuity does not exist, replace armature. Using ohmmeter, check for continuity between commutator and armature coil core. If continuity exists, replace armature.
2. Inspect commutator for dirty or burnt surfaces. Repair as necessary using No. 400 sandpaper or a lathe. Place commutator on "V" blocks. Using a dial gauge, measure circle runout. See «STARTER SPECIFICATIONS»(ref-168674-S19681396372004111500000) . Repair as necessary using a lathe.
3. Using a vernier caliper, measure commutator diameter. See «STARTER SPECIFICATIONS»(ref-168674-S19681396372004111500000) . If commutator diameter is less than minimum specification, replace armature.
4. Ensure commutator mica undercut depth is clean and free of foreign materials. Smooth out edge. Measure commutator mica undercut depth. See «STARTER SPECIFICATIONS»(ref-168674-S19681396372004111500000) . If undercut depth is less than minimum specification, correct depth by using a hacksaw blade to remove mica from between segments.

FIELD COIL TEST

Using ohmmeter, check for continuity between starter solenoid lead and field coil brush lead. If continuity does not exist, replace field frame. Using ohmmeter, check for continuity between field coil end and field frame. If continuity exists, repair or replace field frame.

IGNITION SWITCH TEST (2004)

Using ohmmeter, measure resistance between specified terminals. For terminal identification (Scheme 3) For resistance specifications, see IGNITION SWITCH CONNECTOR RESISTANCE. If the resistance is not as specified, replace switch.

IGNITION SWITCH CONNECTOR RESISTANCE

Scheme 3