Generator No-Load Test
NOTE:
In order to check the charging system, the use of Rotunda Starting and Charging Tester (VAT-40) 078-00005 or equivalent tester is suggested. Refer to the Rotunda Starting and Charging Tester VAT-40 Test Procedure Manual for complete directions on checking out the charging system. Battery posts and cable clamps must be clean and tight to ensure accurate meter indications.
NOTE:
When performing charging system tests, turn OFF all lamps and electrical components. Place transmission in PARK and apply parking brake.
CAUTION:
Do not allow any metal object to come in contact with the housing and internal diode cooling fins with key on or off or short circuit will result and burn out diodes.
- Switch the Rotunda Starting and Charging Tester VAT-40 (078-00005) or equivalent to the voltmeter function.
- Connect the voltmeter positive lead to the generator "B+" terminal (Black/Orange wire) and the negative lead to ground. See Figure.
- Turn all electrical accessories off.
- With the engine running at 2000 RPM, check the generator output voltage. The voltage should be between 13.0 and 15.0 volts. If voltage is not as specified, repair by symptom. See SYMPTOM INDEX table under SYSTEM TESTS.