GM Service Manual Online
For 1990-2009 cars only

Step

Action

Values

Yes

No

1

Check fuses EF20, F19 and F14.

Are fuses EF20, F19 and F14 blown?

--

Go to Step 2

Go to Step 3

2

  1. Check for a short circuit and repair it, if necessary.
  2. Replace the blown fuses.

Is the repair complete?

--

System OK

--

3

  1. Use a voltmeter to test for battery voltage at fuses EF20 and F19.
  2. Turn the ignition ON and test for battery voltage at fuse F14.

Is the voltage equal to the specified value at fuses EF20, F19 and F14?

11-14 V

Go to Step 5

Go to Step 4

4

Repair the power supply circuit to the fuses.

Is the repair complete?

--

System OK

--

5

  1. Remove the cassette radio.
  2. Turn the ignition ON.
  3. Use a voltmeter to test for battery voltage at the audio system connector terminals 4 and 5.

Is the battery voltage equal to the specified value at both terminals?

11-14 V

Go to Step 7

Go to Step 6

6

Repair the open circuit between the audio system connector and the fuse.

Is the repair complete?

--

System OK

7

Use an ohmmeter to test the resistance between ground and terminal 14 of the audio system connector.

Is the resistance equal to the specified value?

∞ Ω

Go to Step 9

Go to Step 8

8

Repair the open ground circuit between the audio system connector and ground.

Is the repair complete?

--

System OK

--

9

Replace the audio system.

Is the repair complete?

--

System OK

--