Charging System - Generators & Regulators: Other Toyota MR2 W30

BELT TENSION

Serpentine drive belt uses an automatic belt tensioner, so no adjustment is necessary, but must be properly installed. 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-166229-S40069383832004091600000) .
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 assembly 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 assembly.

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-166229-S40069383832004091600000) .
2. Check rotor for shorts to ground by connecting ohmmeter between slip ring and rotor shaft. Ohmmeter should indicate no continuity. Check slip rings for wear or pitting. See «GENERATOR SPECIFICATIONS»(ref-166229-S40069383832004091600000) . If slip rings are shorted to rotor shaft, rough or scored, replace rotor.

STATOR

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

Connect ohmmeter between stator leads. Continuity should exist between all stator leads. Connect ohmmeter between stator lead and drive end frame assembly. Continuity should not exist. If stator does not test as indicated, replace drive end frame assembly.

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 CHARGING CIRCUIT under STARTING/CHARGING in SYSTEM WIRING DIAGRAMS article.

2004

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