DESCRIPTION
The charging system consists of an alternator with an internally mounted solid state regulator. The rectifiers bridge contains 6 diodes that changes AC current into DC current. The regulator is preset at the factory, and cannot be adjusted.
TROUBLE SHOOTING
Note. See the TROUBLE SHOOTING - BASIC PROCEDURES article in the GENERAL TROUBLE SHOOTING section.
NO LOAD TEST
- Connect the negative test lead of an ammeter to disconnected wire from terminal "B" on alternator. Connect positive test lead to terminal "B" on alternator.
- Connect positive test lead of voltmeter to terminal "B" on alternator. Connect negative test lead to a good ground. Start engine. At 2000 RPM, check ammeter and voltmeter readings. Amperage should be less than 10 amps. Voltage should be 13.5-15.1 volts.
- If voltage is more than specified, replace regulator. If voltage is less than specified, turn engine off. Ground terminal "F". Start engine and check voltage at terminal "B". If voltage is greater than specified, replace regulator. If voltage is less than specified, check alternator.
LOAD TEST
With engine at 2000 RPM, turn headlights on high beam, and heater fan control switch to "HI" position. Check ammeter reading. If ammeter reading is less than 30 amps, repair or replace alternator.
Note. Sometimes when battery is fully charged, reading may be less than 30 amps.
ROTOR
Using an ohmmeter, inspect rotor for an open circuit and check for continuity between slip rings. If there is no continuity, replace rotor. Inspect rotor for ground and check that there is no continuity between slip ring and rotor. If there is continuity, replace rotor. Check that slip rings are not rough or scored. If slip rings are rough or scored, replace rotor.
STATOR
Using an ohmmeter, inspect stator for open circuit and check for continuity between all stator leads. If there is no continuity, replace drive end from assembly. Inspect that stator is not grounded. Check that there is no continuity between coil leads and drive end frame. If there is continuity, replace drive end frame assembly.
BRUSH & BRUSH HOLDER
Measure exposed length of brush. Minimum length of brush is .177" (4.5 mm). If brush length is less than minimum, replace brush. If brush replacement is necessary, unsolder and remove brush and spring. Insert brush wire through spring and insert brush holder. Solder wire back onto brush holder. Check that brush moves smoothly in brush holder.
BEARINGS
Check that alternator front bearing is not rough or worn. If bearing is rough or worn, replace bearing. When replacing alternator bearing, remove 4 screws and bearing retainer. Replace alternator bearing.
Check that alternator rear bearing is not rough or worn. If bearing is rough or worn, replace bearing. When replacing alternator rear bearing, use a 2 jaw puller. Remove rear bearing with bearing cover from rotor shaft. Using puller, install rear bearing and bearing cover onto rotor shaft.
DISASSEMBLY
Remove 3 end cover retaining nuts. Remove end cover. Remove 5 screws retaining brush holder and regulator. Remove 4 screws retaining rectifier holder and rubber insulators. Remove the pulley using Holding Tool (J-35452) and a breaker bar, by turning the socket clockwise. (Scheme 2)
Exploded View of Nippondenso Alternator. Scheme 1
Removing Pulley. Scheme 2
REASSEMBLY
Check brushes. If brush is not exposed .177" (4.5 mm), replace brush. Check bearings and rotor shaft for roughness or damage. Replace if necessary. Reverse disassembly procedure for reassembly.
See also:
• TROUBLE SHOOTING - BASIC PROCEDURES