I bought a 1995 Camaro that had no speakers or head unit in it. Finally came time to putting audio in it and I've been stuck with no sound from my speakers. This is the base camaro without the bose system so there is not a factory amp in the system. In the wiring harness there was no blue wire for an amp. I wired up the new aftermarket head unit and all my wiring is done correct to the best of my knowledge. The receiver turns on and even connects to my phone via Bluetooth no problem. However, no sound from the speakers. No voltage at the speaker wires. What could cause this?