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For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1999 🢒 GMC P42 Commercial Chassis 🢒 Body and Accessories 🢒 Lighting Systems 🢒 Instrument Panel Lamps Do Not Dim

Instrument Panel Lamps Do Not Dim P32/42

Step

Action

Value(s)

Yes

No

1

Place the headlamps switch in the PARK or HEAD position.

Do the instrument panel (IP) lamps illuminate?

--

Go to Step 2

Go to Instrument Panel Lamps Inoperative

2

Rotate the IP lamps dimmer switch rheostat from full brightness to full dim.

Do the IP lamps brighten and dim?

--

System OK

Go to Step 3

3

Disconnect the IP lamps dimmer switch.

Do the IP lamps remain illuminated?

--

Go to Step 4

Go to Step 6

4

Remove the INSTR LPS fuse from the IP fuse block.

Do the IP lamps remain illuminated?

--

Go to Step 5

Go to Step 7

5

Repair short to B + in CKT 8 (GRY).

Is the repair complete?

--

System OK

--

6

Replace the IP lamps dimmer switch.

Is the repair complete?

--

System OK

--

7
  1. Repair short to B + between cavity D of the IP lamps dimmer switch connector and the IP fuse block cavity H 4.
  2. Reinstall the INSTR LPS fuse.

Is the repair complete?

--

System OK

--

Instrument Panel Lamps Do Not Dim P 32 Export

Step

Action

Value(s)

Yes

No

1
  1. Turn the ignition switch to the OFF position.
  2. Place the headlamps/panel dimmer switch to the PARK position.

Do the instrument panel (IP) lamps illuminate?

--

Go to Step 2

Go to Instrument Panel Lamps Inoperative

2

Rotate the IP lamps dimmer switch rheostat from full brightness to full dim.

Do the IP lamps brighten and dim?

--

System OK

Go to Step 3

3

Disconnect the headlamps/panel dimmer switch.

Do the IP illumination lamps remain lit?

--

Go to Step 4

Go to Step 6

4

Remove the INSTR LPS fuse from the IP fuse block.

Do the IP ilumination lamps remain lit?

--

Go to Step 5

Go to Step 7

5

Repair short to B + in CKT 8 (GRY) between IP fuse block cavity H 3 and the IP cluster connector, cavity 29.

Is the repair complete?

--

System OK

--

6

Replace the Headlamps/panel dimmer switch.

Is the repair complete?

--

System OK

--

7
  1. Repair the short to B + between the headlamps/panel dimmer switch connector, cavity E and cavity H 4 of the IP fuse block.
  2. Reinstall the INSTR LPS fuse.

Is the repair complete?

--

System OK

--