Question about Rockford Fosgate Punch 401S Car Audio Amplifier

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Weird sounds coming through speakers

I can listen to the stereo fine as long as I don't start my car but if I start it a weird sound comes through the speakers and gets louder as RPM builds. Is there a way to get rid of this or is the amp screwed? I just replaced the battery and the alternator. And was told that it could be a bad ground but I have reran the ground and shortened it and its still making the sound. Thanx

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Re: Weird sounds coming through speakers

The problem is not likely the amp. The length of the ground to the amp is not as critical as a good solid connection. Clean any paint and dirt from around the ground connection. It should be clean and shiny metal. Anyway as a test disconnect the RCA's from the amp while the amp is on and see if the sound goes away. If it does then the problem is not in the amp but either the RCA cables, the RCA grounds in the head unit (radio) or bad routing of the RCA cables. Depending on the how old the car is this noise can be coming from your spark plug wires as well. As a last resort you can try a new set of supressor ignition wires for the car.

Posted on Jul 14, 2007

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