GMC Repair: GMC Dome / Back-up Light Problem, push button switch, override switch

Question
2003 GMC Sierra - Interior lights and backup lights have quit working. These are also used for surround illumination. All fuses are good. Dome override switch NOT engaged.

Already Tried:
Checked all fuses, bulbs. Int. map dome lites work on the push button switch, not on opening the door or when unlocking or departure lites.

Thanks,
Jake  

Answer
hi
If you could have vehicle checked with a scan tool that has ability to see BODY data, this would cut diagnostics in half. See if BCM is commanding reverse lights/dome lamps ON
Both item you are having problems with have 2 common components, the BCM (Body control module) and the IP fues block (drivers side fuse box) I can also tell you I have replaced them both for mulitiple faults, such as you are experiencing.
Keep in mind also, you MAY have a wire problem with multiple wires chaffed/cut in harness in the drivers floor area, OR somewhere in harness, say possible due to rodents, etc...
These are JUST suggestions.
Good Luck
God Bless