Interior Backlighting Does Not Dim

WARNING: This page is about a different car, the 2006 Pontiac Montana SV6, 2006 Chevrolet Uplander, and 2006 Buick Terraza. 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. Turn the headlamps ON. Place the instrument panel (I/P) lamp dimmer switch in the full bright position, then slowly to the full dim position. Do the dimming lamps operate normally?	Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems	Go to Step 3
3	Test the I/P dimming reference voltage and I/P dimming control circuits of the headlamp switch for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 7	Go to Step 4
4	Test for a short to battery positive voltage in the I/P lamp supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 7	Go to Step 5
5	Inspect for poor connections at the harness connector of the headlamp switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 7	Go to Step 6
6	Replace the headlamp switch. Refer to Headlamp Switch Replacement . Did you complete the replacement?	Go to Step 7	-
7	Operate the system in order to verify the repair. Did you correct the condition?	System OK	Go to Step 4