Step  | Action  | Yes  | No  | 
|---|---|---|---|
Schematic Reference: Interior Lights Dimming Schematics Connector End View Reference: Lighting Systems Connector End Views or Instrument Panel, Gages, and Console Connector End Views in Instrument Panel, Gages, and Console  | |||
1  | Did you perform the Diagnostic System Check - Vehicle?  | Go to Step 2  | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information  | 
2  | Verify that the interior backlighting is inoperative. Does the interior backlighting operate normally?  | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems  | Go to Step 3  | 
3  | Are the instrument panel cluster (IPC) backlighting lamps the only lamps that are inoperative?  | Go to Step 4  | Go to Step 5  | 
4  | Test the instrument panel (I/P) lamp fuse supply voltage circuit to the instrument cluster connector for an open or high resistance. Refer to Circuit Testing in Wiring Systems. Was a problem found?  | Go to Step 10  | Go to Step 11  | 
5  | With the headlamp switch in the PARK position, move the dimmer rheostat from low to high while using a test lamp to ground to check for voltage at the ILLUM fuse in the I/P fuse block. Refer to Circuit Testing in Wiring Systems. Does the test lamp illuminate from dim to bright at one or more of the fuse test points?  | Go to Step 6  | Go to Step 7  | 
6  | Test the I/P lamp fuse supply voltage circuit for a short to ground. Refer to Circuit Testing in Wiring Systems. Was a problem found?  | Go to Step 9  | Go to Step 10  | 
7  | Move the rheostat from low to high while using a test lamp to ground to check for voltage at the I/P lamps dimmer switch signal terminal of the headlamp switch. Refer to Circuit Testing in Wiring Systems. Does the test lamp illuminate from dim to bright?  | Go to Step 8  | Go to Step 12  | 
8  | Repair the open or high resistance in the I/P lamps dimmer switch signal circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?  | Go to Step 13  | --  | 
9  | Repair the short to ground in the I/P lamp fuse supply voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?  | Go to Step 13  | --  | 
10  | Repair the open or high resistance in the I/P lamp fuse supply voltage circuit or the ground circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?  | Go to Step 13  | --  | 
11  | Replace the IPC. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the repair?  | Go to Step 13  | --  | 
12  | Replace the headlamp switch. Refer to Headlamp Switch Replacement . Did you complete the repair?  | Go to Step 13  | --  | 
13  | Operate the system in order to verify the repair. Did you correct the condition?  | System OK  | Go to Step 3  |