Generator Assembly Check. Cadillac Concours 1996

For 1990-2009 cars

1. Check the belt for wear and tension.
2. Check the wiring.
3. With the ignition switch ON and the engine OFF, the lamp should be on. If not, disconnect the wiring harness at the generator and use a fused jumper wire with a 5 amp fuse, in order to ground the L terminal lead and diagnose the following situations:

• | If the lamp turns on, replace the generator. Refer to Generator Replacement

• | If the lamp does not turn on, locate the open circuit between the grounding lead and the ignition switch. The lamp may be open.

4. With the ignition switch ON and the engine running at a moderate speed, the lamp should be off. If not, stop the engine, turn the ignition switch ON, and disconnect the wiring harness at the generator in order to diagnose the following situations:

• | If the lamp goes out, replace the generator. Refer to Generator Replacement

• | If the lamp stays on, check for a grounded L terminal wire in the harness.

5. If the battery is undercharged or overcharged, or the vehicle's voltmeter shows high or low voltage with the engine running perform the following procedure:

5.1. | Disconnect the electrical connector from the generator.

5.2. | With the ignition switch ON and the engine OFF, connect the J 39200 , set on DC voltage scale, from the ground to the L terminal in the wiring harness and to the I terminal if used. The wiring harness may connect to either I or both.

5.3. | The voltage should be B+, other readings indicate an open, high resistance, or a grounded circuit between the terminal and the battery. Correct as required.

5.4. | Connect the electrical connector to the generator and run the engine at moderate speed with all the accessories off.

5.5. | Measure the voltage using the J 39200 across the battery. If it is above 16 volts, replace the generator. Refer to Generator Replacement

5.6. | With the engine OFF, connect an ammeter at the generator output terminal. The ammeter must have current capability of at least 115 amps. Connect the J 39200 across the generator and a carbon pile across the battery.

5.7. | Run the engine at 2500 RPM, turn on the accessories, and load the battery with a carbon pile in order to obtain the maximum amperage. Maintain the voltage at 13 volts or above.

• | If the output in amperes is within 15 amperes of the rated output, the generator is OK.

• | If the output is not within 15 amperes of the rated output, replace the generator. Refer to Generator Replacement