I have a high pitched whine when I listen to am radio even when the car is not running. I checked the ground at the amp and all is good (12.99 volts) without the alternator. The radio is powered by the starter battery and the amp is powered by the deep cycle battery. Both are grounded to the chassis. Any tips for fixing it?

 

where are your rca's run ??? where is the power for the amp run ???

 

What is your headunits grounded 2?

 

The rca's are run down the middle of the truck and the power cable comes down the passenger side and across the back to the driver's side. My crossovers are sitting a few inches above the 4 gauge power and ground cables. After searching the board, I think I will move the crossovers and see if that helps. Then I will run a ground wire from the HU to the same ground point as the amp. The amp is grounded to one the seatbelt bolts under the rear seat. I used a dmm and I'm getting 12.99 volts between the power terminal and the ground terminal. And, I getting12.98 volts between the power terminalat the amp and the ground bolt, so I think the ground is good. My other option is to running the ground back to the battery. I can test it by runninga jumper cable between the amp and the battery. The radio is grounded to the factory ground wire in the factory harness. I plan to work on it over the weekend. Let me know if I am on the right track and thanks for the help so far. I am sure it will be something simple.

PS: FM does not have a whine.

 

Forum ***** Ha Ha!

 

Sounds like your on the rite track.