My 2003 Yukon XL is blowing the TBC 2B fuse. I have tracked down the problem to the wire (#690) in the C5 connector at the Body Control Module. When I remove this wire from the BCM connector, the TBC 2B fuse is okay. Once I plug the wire back into the BCM, the TBC 2B immediately blows the fuse. The #690 wire circuit controls the dome lights and with the wire disconnected the dome lights will not turn on when the doors are opened or when I manually rotate the switch. I am hoping it is a short in the #690 wire and not a faulty BCM.

I would like to continue trouble shooting my issue but I cannot find a dome light wiring diagram for a 2003 - 2006 Yukon XL / Suburban. My owners manual and Chilton's manual do not have a wiring diagram showing the dome light system. Does anyone have or know where I can get one?

The C5 connector also controls the reverse / back up lights. With wire circuit #690 disconnected at the BCM, and the TBC 2B fuse no longer blows and my back up lights are now working.

 

Ok this is going to sound crazy but look into the bulk head connector in your rear hatch up by the 3rd brakelight. Run a ground wire through the rubber boot and ring term to "sheetmetal" rear hatch. The other end ring term and ground to body. This will fix the bad ground in your issue.