RPM dependent buzz in Monsoon system
I got a replacement 02 monsoon deck and plugged it in and now I have a buzz (similar to a ground loop) that changes pitch with RPM. It happens if the radio/cd is on OR off (but only with the engine running). The rest of the system works perfectly. The buzz noise will only go away if I completely unplug the deck from the harness.
I thought maybe I got a bad head unit with a bad ground so I tried a friends deck and still have the same buzzing.
Do you think I fried the amp back by the spare tire when I briefly shorted the light leads when I was checking polarity? It seems like the noise is coming mostly from the rear hatch speakers. Could I have back fed something into the alternator messing that up? The charging system seems to be working fine (putting out 14+V withe the engine running with my multi-meter), but it is the original alternator with 85k miles on it.
The buzzing seems to get more pronounced with more of a draw on the electrical system (lights on, defroster on, brake lights on, etc...).
I'd like to not band-aid this with a ground-loop isolator if I don't have to.
Thanks for any help.
I can't believe I didn't try that first






