I am replacing the factory head unit (not Bose system) with a Pioneer DEH-P630. I bought the wiring harness adapter and crimped all of the connections, plugged it up and power came on fine. The problem is there was no sound from the speakers.
The vehicle does have a factory subwoofer (ergo there must be a factory amp), so I'm wondering if there isn't an accessory wire that i need to hook up other than the main wire harness. There were two connections on the back of the radio but I thought the smaller was the On-Star hook up.