I'm running a 4 channel Fusion FP504 Amp, and it has been giving me a lot of engine noise. I took the car to Tonkins (Car audio specialists, know what they are doing) and they tried everything they could to get rid of the engine noise, but couldn't do it. They suggested it was probably an issue with the amp, and they could send it back to the manufacturer under warranty.

The next part of the story, however is that my friend has the exact same amplifier, which worked fine in his car for a long time, until he had his alternator rebuilt. From this point on the engine noise was prominent, as it seems because the alternator is putting out too much power. Would this be an issue with a 5th gen accord''s alternator? As far as I know the alternator has never been rebuilt or repaired.

Any ideas from the backyard professional in all of you ?