I searched for a solution before posting a new thread but have yet to find an answer. So here is the issue...

I have an 85 IROC which had the stock stereo and speakers still in it. The front speakers worked and no sound came from the rear speakers. So, I bought all new speakers (front and back) and a new head unit. I tested all the speakers on a home stereo before install and they all worked fine. When installed I got no sound from the front or the back with the original HU connected. I hooked up the new HU and still no sound front or back. So I'm looking for some answers or starting points to find the answers to my problem. The car is all stock with 40K original miles just to give you an idea of the condition of the car. All the wiring appears to be in tiptop shape from what I can see. I tested the factory speakers on the home stereo and the front ones worked as they did in the car and the rear ones did not.

 

Solved. Disconnected the rear speakers and the front ones started working. Found a short in the rear driver side speaker. Now if I could only figure out how to delete this thread...

 

If the speaker was shorted there is good possibility that one of the output IC's in the radio went...You will know by adjusting the balance and fade. One or more speakers will have a weak or quiet output.