Interior Backlighting Does Not Dim

WARNING: This page is about a different car, the 2005 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.

Step	Action	Yes	No
Schematic Reference: Interior Lights Dimming Schematics Connector End View Reference: Master Electrical Component List in Wiring Systems
1	Did you perform the Diagnostic System Check - Vehicle?	Go to Step 2	Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2	Turn ON the ignition, with the engine OFF. Place the headlamp switch in the PARK position. Cycle the instrument panel (I/P) lamp dimmer switch from maximum to minimum. Do the I/P lamps dim?	Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems	Go to Step 3
3	Install a scan tool. With a scan tool, command the I/P dimming lamps ON and OFF in the Instrument Panel (I/P) Special Functions list. Do the I/P lamps dim from maximum to minimum intensity with the scan tool commands?	Go to Step 4	Go to Step 7
4	Locate and repair an open, high resistance, or short to ground in the I/P lamps dimmer switch up signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 11	Go to Step 5
5	Locate and repair an open, high resistance, or short to ground in the I/P lamps dimmer switch down signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 11	Go to Step 6
6	Locate and repair an open or high resistance in the I/P dimmer switch ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 11	Go to Step 8
7	Inspect for poor connections at the harness connector of the instrument panel cluster (IPC). 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 11	Go to Step 10
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 11	Go to Step 9
9	Replace the I/P dimmer switch. Refer to Instrument Panel (I/P) Dimmer Switch Replacement . Did you complete the replacement?	Go to Step 11	-
10	Replace the IPC. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?	Go to Step 11	-
11	Operate the system in order to verify the repair. Did you correct the condition?	System OK	Go to Step 2