For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: Interior Lights Dimming Schematics
1 | Did you perform the Lighting System Diagnostic System Check? | Go to Step 2 | Go to Symptoms - Lighting Systems
2 |

1. Place the headlamp switch in the PARK position.
2. Operate the Instrument Panel (I/P) dimmer switch.

Do the instrument panel lamps operate properly?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3 |

1. Place the headlamp switch in the OFF position.
2. Disconnect the I/P dimmer switch.
3. Probe the instrument panel lamp fuse supply voltage circuit of the I/P dimmer switch with a test lamp that is connected to a good ground.
4. Place the headlamp switch in the PARK position.

Does the test lamp illuminate?

Go to Step 4

Go to Step 10

4 |

1. Place the headlamp switch in the OFF position.
2. Connect a 15 amp fused jumper wire between the instrument panel lamp fuse supply voltage circuit of the I/P dimmer switch and the instrument panel lamps dimmer switch signal circuit of the I/P dimmer switch connector.
3. Place the headlamp switch in the PARK position.

Do the instrument panel lamps illuminate?

Go to Step 8

Go to Step 5

5 |

1. Leave the fused jumper wire connected.
2. Place the headlamp switch in the OFF position.
3. Disconnect the I/P dimming module.
4. Probe the instrument panel lamps dimmer switch signal circuit of the I/P dimmer switch at the I/P dimming module connector with a test lamp that is connected to a good ground.
5. Place the headlamp switch in the PARK position.

Does the test lamp illuminate?

Go to Step 6

Go to Step 11

6 | Connect a 15 amp fused jumper wire between the instrument panel lamps dimmer switch signal circuit of the I/P dimmer switch and the instrument panel lamps dimmer switch signal circuit of the I/P dimming module at the I/P dimming module connector.

Are the instrument panel lamps illuminated?

Go to Step 7

Go to Step 12

7 | Test the instrument panel lamp fuse supply voltage circuit of the I/P dimming module for an open, high resistance, or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 15 | Go to Step 9
8 | Inspect for poor connections at the harness connector of the I/P dimmer switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 15 | Go to Step 13
9 | Inspect for poor connections at the harness connector of the I/P dimming module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 15 | Go to Step 14
10 | Repair an open, high resistance, or short to ground in the instrument panel lamp fuse supply voltage circuit of the I/P dimmer switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 15 | --
11 | Repair an open, high resistance, or short to ground in the instrument panel lamps dimmer switch signal circuit of the I/P dimmer switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 15 | --
12 | Repair an open, high resistance, or short to ground in the instrument panel lamps dimmer switch signal circuit of the I/P dimming module. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 15 | --
13 | Replace the I/P dimmer switch. Refer to Instrument Panel Lamp Dimmer Switch Replacement . Did you complete the replacement? | Go to Step 15 | --
14 | Replace the I/P dimming module. Refer to Panel Dimming Module Replacement . Did you complete the replacement? | Go to Step 15 | --
15 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 3