I have a 2003 2-door Blazer. The back lights for the instrument cluster, heater controls, and gear shift positions quit working (intensity is controlled by the dimmer control). All other electrical works OK. My auto repair guy replaced the headlight control module, and it smoked in less than 24 hours, killing the circuit. He replace the module a second time with same results. Any suggestions for this?
I would guess you have an interment short somewhere. Those are tough to find.