Generators & Regulators: Other Lexus SC II

BELT TENSION

Generator is driven by a serpentine drive belt. Belt tension is maintained by an automatic belt tensioner. No adjustment is necessary. For belt routing (Scheme 5)

Scheme 5

BRUSHES

1. Brushes should slide smoothly in holders. Replace brushes if damaged or worn. See «GENERATOR SPECIFICATIONS»(ref-167969-S29551613542004102600000) .
2. If exposed brush length is less than minimum, replace brushes and brush holder assembly. Install new brush springs when replacing brushes.

DIODES

1. With diode/rectifier holder removed and on bench, contact positive diode plate terminal with one ohmmeter probe. Using other ohmmeter probe, contact each diode lead in same plate. Note ohmmeter reading. Reverse ohmmeter probes, and repeat tests for all diodes.
2. All diodes should show continuity in one direction and no continuity in opposite direction. If any diode is defective, replace diode/rectifier holder.

ROTOR

1. Check rotor for open field windings by using an ohmmeter across slip rings. Rotor resistance should be within specification. See «GENERATOR SPECIFICATIONS»(ref-167969-S29551613542004102600000) . If resistance reading is not as specified, replace rotor.
2. Check rotor for grounded field windings. Using an ohmmeter, check for continuity between slip ring and rotor. Continuity should not be present. If continuity is present, replace rotor.
3. Check slip rings for wear or pitting. If slip rings are rough, scored or less than minimum diameter, replace rotor.

STATOR

Note. Stator may also be referred to as drive end frame.

1. Check for open circuit in stator windings. Using ohmmeter, check for continuity between coil leads. If continuity is present, go to next step. If continuity is not present, replace drive end frame.
2. Check for shorted stator windings. If continuity is present between stator terminals and drive end frame, replace drive end frame.

VOLTAGE REGULATOR

Note. When positive and negative probes between terminals are exchanged, there is continuity in one direction but not in the other direction.

Using ohmmeter, check for continuity between following

1. Terminals "F" and "B"
2. Terminals "F" and "E"

If continuity is not as specified, replace voltage regulator. See

(Scheme 6)

Scheme 6

2003

For 2003 models, go to STARTING/CHARGING in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.

2004

For 2004 models, go to STARTING/CHARGING in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.