Ok I just bout an 05 yukon Denali, basically stock except for an alarm and amp wired up. Well on the first night I noticed none of the dome lights were working except for the drivers door entry light. I checked the bulbs in the dome lights no they were fine, checked the switch and that worked only illuminating the drivers door, dome over ride works but only on that door as well. ( Ill check the passenger door light bulb tomorrow )

Also the reverse lights are the same, no lights but fuse is fine and wiring intact.

So I figured the alarm must have turned off the dome lights, so I took it to the cartoys where it was installed and they said they didn't do that, and can't. The install guy looked at it real quick and said its not the alarm. What else could it be?

Last guess is the bcm, maybe programmed off if it can do that?