GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value

Yes

No

1

  1. Disconnect the generator connector.
  2. Turn the ignition switch to RUN.
  3. Connect a voltmeter J 39200 from the BRN 25 wire at the generator connector and to ground.

Is the voltage reading within the specification?

Battery voltage

Go to Step 2

Go to Step 4

2

Connect a voltmeter from the BAT terminal at the generator and to ground.

Is the voltage reading within the specification?

Battery voltage

Go to Step 3

Go to Step 8

3

  1. Reconnect the generator connector.
  2. Turn OFF all of the accessories.
  3. Run the engine at 2,000 RPM.
  4. Connect a voltmeter J 39200 across the battery terminals.

Is the voltage reading within the specifications?

13-16 V

Go to Step 9

Go to Step 4

4

Perform a generator bench check. Refer to Generator Assembly Bench Check.

Is the voltage reading within the specifications?

13-16 V

Go to Step 9

Go to Step 10

5

Backprobe the BRN 25 wire at the I/P cluster connector with a voltmeter J 39200 to ground.

Is the voltage reading within the specification?

Battery voltage

Go to Step 11

Go to Step 6

6

Backprobe the PNK 39 wire at the I/P cluster connector terminal 28 with a voltmeter J 39200 to ground.

Is the voltage reading within the specification?

Battery voltage

Go to Step 12

Go to Step 7

7

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

Has the repair been completed?

--

System OK

--

8

Repair RED 2 wire from the S106 to the generator.

Has the repair been completed?

--

System OK

--

9

Perform a battery load test. Refer to Battery Load Test .

Is the battery serviceable?

--

Go to Step 14

Go to Step 13

10

Install a replacement generator. Refer to Generator Replacement in Engine Mechanical.

Has the repair been completed?

--

System OK

--

11

Locate, repair open in BRN 25 wire from the I/P cluster to the generator.

Has the repair been completed?

--

System OK

--

12

  1. Battery tell tale filament open.
  2. If OK, install a new I/P cluster.

Has the repair been completed?

--

System OK

--

13

Install a battery. Refer to Battery Replacement .

Has the repair been completed?

--

System OK

--

14

Charge the battery. Refer to Battery Charging.

Has the repair been completed?

--

System OK

--