Generators & Regulators: Other Lexus LS III

ES300 & RX300

Check belt tension using Burroughs Tension Gauge (BT-33-73F) at longest belt run. For a new belt, tension should be 150-185 lbs. (68-84 kg). For a used belt, tension should be 95-135 lbs. (43-61 kg). Adjust belt tension if necessary.

Except ES300 & RX300

Apply 22 lbs. (10 kg) force to top belt run. Belt tensioner should move downward, and pointer on belt tensioner should fall within area "A" (used belt) or area "B" (new belt). (Scheme 11)or (Scheme 12). If pointer does not fall within specified area, replace belt or belt tensioner as necessary.

Scheme 11

Scheme 12

Except LS430

1. Connect charging system test equipment following manufacturer's instructions. Check charging system output voltage at 2000 RPM. See «GENERATOR OUTPUT SPECIFICATIONS»(ref-91434-S26798095212001031400000) table. If output voltage is high, replace voltage regulator and retest. If output voltage is low, go to next step. If output voltage is correct, go to step 3.
2. If output voltage is low, by-pass regulator (full field generator) by grounding terminal "F" at back of generator. (Scheme 13)or (Scheme 14). Recheck charging system output voltage. See «GENERATOR OUTPUT SPECIFICATIONS»(ref-91434-S26798095212001031400000) table. If output voltage is high, replace voltage regulator and recheck. If output voltage remains low, repair or replace generator.
3. With engine at 2000 RPM, place heater blower switch on highest setting and turn on headlights (high beam). Ammeter reading should be 30 amps or more. If amperage output is less than 30 amps, repair or replace generator.

GENERATOR OUTPUT SPECIFICATIONS

Scheme 13

Scheme 14

LS430

1. Disconnect wire from generator terminal "B". Connect ammeter and voltmeter as indicated. (Scheme 15) Operate engine at idle and increase to 2000 RPM. Check generator output. See «GENERATOR OUTPUT SPECIFICATIONS»(ref-91434-S26798095212001031400000) table. If output voltage is high, replace voltage regulator and recheck. If output voltage remains low, repair or replace generator.
2. With engine at 2000 RPM, place heater blower switch on highest setting and turn on headlights (high beam). Ammeter reading should be 30 amps or more. If amperage output is less than 30 amps, repair or replace generator.

Scheme 15

BRUSHES

Check brushes for cracks and a minimum exposed length of .059" (1.5 mm). Replace complete brush holder assembly if brushes are damaged or worn.

ROTOR

1. Check rotor for open field windings by measuring resistance across slip rings. Resistance should be within specifications. See «ROTOR RESISTANCE SPECIFICATIONS»(ref-91434-S11068518842001031400000) table. Check rotor for short circuit to ground by connecting ohmmeter between one slip ring and rotor. Continuity should not exist. If resistance and continuity are not as specified, replace rotor.
2. Check slip rings for wear or damage. Turn rotor/slip rings on lathe if necessary. Ensure slip ring diameter is not less than .504" (12.8 mm). Check bearing and replace if necessary.

ROTOR RESISTANCE SPECIFICATIONS

STATOR

Using ohmmeter, check continuity between stator leads. Continuity should exist between all stator leads. Check continuity between stator lead and generator housing. Continuity should not exist. If continuity is not as specified, replace stator.