I installed a new soundsystem (2 amps, cap, sub) on my Accord last night, and this morning, I noticed that when I turned on the rear window defroster, there'd be a squealing/whistling noise coming from the engine. The noise would increase to a higher frequencied pitch as I increased the rpm.

I was wondering if anyone know what could be causing this problem and how to fix it? I never had this problem before the install of the sound system.


Thanks!

 

I think you'll find that noise is actually coming from the speakers, not the engine. A speaker or line level wire is too close to the rear defroster wiring. It's a fairly high amperage line and induces alternator whine.