I have a 2010 camaro had MTX hooked up to speaker level input off rear speakers has smart engage to turn on with stereo. It worked well for over a year til using on-star with it up loud when the voice cut in the amp fried. I got a line out converter hoked that up got a loud burrrrp converter fried. got another MTX hooked it up to rear speakers as before worked fine two weeks. With out radio on it started hitting a base note first soft not sure if I was hearing it about 20 min later it was hitting so hard it was going to shake my car apart. only stopped when car off. checking signals and there is fluctuating DC voltage with car on +-6 v to the stock speakers I have tapped off. With the radio loud as much as 30 DC V. On-star 60 DC V spikes. I'm going to try a ground loop isolator and line out converter next. Anyone dealt with DC V out of stock head unit? how to get rid of it? or a amp that can handle it. Thanks for your help!!
