For the past 2 weeks, I've had this high high pitched squeel come from the speakers. This occurs suddenly when I'm driving and the day is usually hot (90+ degrees).

The squeel stops after I turn off the HU. I did some testing today and unplugged the RCA's and found that the squeel continues still. My guess is that its the amp? After I tried the RCA's I turned off the HU, unplugged a speaker wire from a single channel and turned the HU back on. The squeeling stopped. Then I turned the HU back off and plugged it back in and turned the HU back on and to my surprise there was still no squeeling.

I don't have the faintest idea of why this would happen. Anyone care to put in some input?

 

Maybe a bad ground?

 

I actually troubleshooted it down to a bad 3rd channel. It pretty much started to fail slowly and now its 100% dead. bummer.