Two problems related to wiring have been reported for the 2004 GMC Envoy. The most recently reported issues are listed below.
GMC dealer service tech found the wire to rear defroster corroded and broken. Repaired wiring.
Since car is new we continue to have melting issue with wiring and harness behind radio rack and areas that are affected in this instrument cluster. This has happened so many times GMC has extended the warranty on car to cover all of the car. It is again causing a problem, lights out on cluster, lighter inop, heater and a/c fans not always working.