GM Service Manual Online
For 1990-2009 cars only

Step

Action

Normal Result(s)

Abnormal Result(s)*

1

Visually inspect the battery for physical damage.

Battery case is not cracked or broken.

Battery case is cracked or broken. Refer to Fastener Tightening Specifications . Refer to Battery Replacement .

3

Visually inspect the battery's built-in hydrometer

Battery hydrometer displays a green dot.

Battery does not display a green dot. Refer to Battery Hydrometer Displays Yellow Dot .

4

Check The battery performance. Refer to Battery Not Operating Properly .

Battery passes the load test.

Battery does not pass the load test. Refer to Battery Replacement .

5

Inspect the generator output terminal for a loose connection.

Generator output terminal is clean and tight.

Generator output terminal is not clean and tight. Refer to Fastener Tightening Specifications .

6

  1. Turn all electrical loads in the vehicle to OFF.
  2. Turn the ignition switch to the RUN position (engine not running)

Charge indicator in the instrument cluster is lighted.

Charge indicator in the instrument cluster is not lighted. Refer to Charge Indicator Inoperative .

7

Start the engine and allow it to idle briefly.

    • Charge indicator in instrument cluster is not lighted.
    • Volts gauge in instrument cluster is in normal range.
    • Charge indicator in instrument cluster is lighted. Refer to Charge Indicator Always On
    • Volts gauge in instrument cluster is not in normal range. Refer to Voltmeter Displaying High or Low .

8

Increase the engine speed to 2500 RPM.

    • Charge indicator in instrument cluster is not lighted.
    • Volts gauge in instrument cluster is in normal range.
    • Charge indicator in instrument cluster is lighted. Refer to Charge Indicator Always On .
    • Volts gauge in instrument cluster is not in normal range. Refer to Voltmeter Displaying High or Low .

9

Check the engine generator performance. Refer to Generator Assembly Bench Check .

Generator performs properly. System is OK.

Generator fails generator electrical test. Refer to Generator Replacement .

* Refer to the appropriate symptom diagnostic table for the applicable abnormal result.