GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Disconnect the generator connector.
  2. Place the ignition switch in the RUN position.
  3. Connect a voltmeter from BRN (25) wire at the generator connector to ground.

Does voltmeter read battery voltage?

12 V

Go to Step 2

Go to Step 4

2

Connect the voltmeter from terminal BAT at generator to ground.

Does voltmeter read battery voltage?

12 V

Go to Step 3

Go to Step 6

3

  1. Connect the generator connector.
  2. Have all accessories turned off and the engine running at fast idle.
  3. Connect the voltmeter across battery terminals and note the voltage.

Is the voltmeter reading within range?

13-16 V

Go to Step 7

Go to Step 8

4

Backprobe BRN (25) wire at the instrument cluster connector with a voltmeter to ground

Does voltmeter read battery voltage?

12 V

Go to Step 9

Go to Step 5

5

Backprobe PNK (39) wire at the instrument cluster connector terminal 22 with a voltmeter to ground.

Does battery voltage exist?

--

Go to Step 10

Go to Step 11

6

Repair or replace the black/red wire from the fusible link to generator.

Is the repair complete?

 

System OK

--

7

Perform battery load test. Refer to Battery Load Test .

Is the test complete?

--

System OK

--

8

Perform generator bench test. Refer to Generator Assembly Bench Check .

Is the generator okay?

--

Go to Step 7

9

Locate and repair open in BRN (25) wire from the instrument cluster to generator.

Is the repair complete?

--

System OK

--

10

Check the charge indicator filament.

Is the charge indicator filament okay?

--

Go to Step 12

--

11

Locate and repair open in PNK (39) wire from the I/P fuse block to the instrument cluster.

Is the repair complete?

--

System OK

--

12

Replace the instrument cluster.

Is the replacement complete?

--

System OK

--