Quote Originally Posted by 93 525 Paul View Post
Yanked the amp, measured stuff there. The always hot red lead has 12v, the key on hot white/red has 9v. Brown ground leads all have continuity to ground.


I see on the wiring diagram that yellow/black, yellow/blue, and several others come from the head unit, so I tested them for some sort of signal. I'm no wiz, so help me out here. I set the range on 1v on my trusty old analog guage and got no needle movement whatsoever. I see it has an amperage range, but am not familiar with that. Any suggestions or are we now convinced it's the all allong suspect head unit?

Thanks again
if your amp is working properly you should hear a 'thud' from the speakers when you turn the HU on.

attack eagle has some good advice somewhere on bf.com including a pin layout for the factory amp...

i can't really say b/c i never had the stock HU but stock radios generally are garbage in any car in my experience.