Head Up Display (HUD) Intensity Does Not Vary

WARNING: This page is about a different car, the 2004 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.

Step	Action	Yes	No
Schematic Reference: Head Up Display Schematics
1	Did you perform the IPC Diagnostic System Check?	Go to Step 2	Go to Diagnostic System Check - Instrument Cluster
2	Turn ON the ignition, with the engine OFF. Adjust the head up display (HUD) dimmer switch to full intensity, then back to full dim. Does the HUD dim properly?	Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems	Go to Step 3
3	Turn OFF the ignition. Disconnect the HUD display connector. Turn ON the ignition, with the engine OFF. Connect a test lamp between the HUD dim slider circuit and B+ at the IPC. Refer to Circuit Testing in Wiring Systems. Adjust the HUD to full intensity, then back to full dim. Does the test lamp go from full intensity then dim?	Go to Step 6	Go to Step 4
4	Test the HUD dim slider circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 8	Go to Step 5
5	Replace the HUD dimmer switch. Refer to Head Up Display Switch Replacement . Did you find and correct the condition?	Go to Step 8	Go to Step 7
6	Replace the HUD display. Refer to Head Up Display Replacement . Did you complete the replacement?	Go to Step 8	-
7	Replace the IPC. Refer to Instrument Panel Cluster (IPC) Replacement . Did you complete the replacement?	Go to Step 8	-
8	Operate the system in order to verify the repair. Did you correct the condition?	System OK	Go to Step 2