I have a 97 SE with Bose and i had an aftermarket pioneer deck (DEH 3900MP) installed. At first the deck was working fine but it started acting up. I started getting scratchy and popping noises and sometimes cut outs from my passenger side front and rear speakers. Some days it would work fine and all of a sudden I hit a bump and one of theses speakers starts making noise or cuts out. The scratchyness and popping seemed to be directly related to bumps I went over and even if I tapped on the head unit face this would result in the same problem. I figured that i must have a loose connection.

Last weekend i took the dash apart and checked the connections. The wiring harness or adapter thats connected to my pioneer deck into the stock power and speaker harness looked fine but every time I moved the harnesses together or tapped or touched the connection the stereo would either cut out, loose power, or sound scratchy or poppy. I kinda got fed up and put everything back together. Stereo worked fine for half a day but now I have power to the deck and absolutely no sound. I think its a bad harness between my deck and car. Is there something i am missing? Could I possibly also have a bad harness from the car. What can I do to check? Thanks!

 

Did you check the grounds for the harness? Are they loose?

 

No I did not. Which colored wires are the grounds on the harness? Are there any links to wiring diagram? Sorry i'm a newb when it comes to electrical. Thanks again!

 

Check to make sure it is actually grounded (Black wire). It should be grounded directly to the chassis, Not through the harness.