GM Service Manual Online
For 1990-2009 cars only

Step

Action

Values

Yes

No

1

Check the operation of the headlamps and the parking lamps.

Do the headlamps and the parking lamps work on both sides of the vehicle?

--

Go to Step 3

Go to Step 2

2

Repair the headlamps and the parking lamps.

Does the instrument panel illumination turn ON after the headlamps and the parking lamps have been repaired?

--

System OK

Go to Step 3

3

  1. Disconnect the electrical connector at the dimmer control switch.
  2. Turn the parking lamps ON.
  3. Use a voltmeter to check the voltage at the dimmer control switch terminal 3.

Is the voltage within the specified range?

11-14 V

Go to Step 5

Go to Step 4

4

Repair the open circuit between fuse EF21 and the dimmer control switch.

Is the repair complete?

--

System OK

--

5

  1. Turn the lights OFF.
  2. At the disconnected dimmer control switch, use an ohmmeter to check the resistance between ground and terminal 2 of the dimmer switch connector,

Is the resistance equal to the specified value?

~ohms

Go to Step 7

Go to Step 6

6

Repair the open circuit between ground and terminal 2 of the dimmer control switch connector .

Is the repair complete?

--

System OK

--

7

  1. Turn the parking lights ON.
  2. At the disconnected dimmer control switch, check the voltage at terminal 1 of the dimmer control switch.

Is the voltage within the specified range?

11-14 V

Go to Step 9

Go to Step 8

8

Repair the open circuit between connector S204 and terminal 1 of the dimmer control switch.

Is the repair complete?

--

System OK

--

9

Replace the dimmer control switch.

Is the repair complete?

--

System OK

--