Is the onstar LED on at all(green/red)? Does the radio display station info and such, just no audio? What I would do first off, is take both battery cables loose, and touch them together for about 30 seconds. Reconnect them and see if the concern is not resolved. If it is resolved, you had a logic lock condition, not necessarily indicative of a component fault.
Wednesday, February 15th, 2017 AT 2:43 PM