I just picked up a 90 Iroc that has the factory bose system. The factory stereo wasn't working, so I pulled it out to find all of the wires cut. I assume someone had an aftermarket stereo in it and didn't install it properly. I reattached the wires and now have three connectors going to the stock bose headunit. Blue, white, and black I believe. There are other wires there, but I think those are there for cars without the bose option right? When I turn the stereo on, I get a high pitched noise. If I turn the volume all the way up, I can hear some distorted music. Where should I go from here? Are the amps blown? Is it possible something else could be unhooked since there was an aftermarket unit in it at one time? I'd really like to stick with the stock system. Thanks for your help.

The Bose unit is (basically) a preamp, so for it to work well you need bose speakers, in wich there are 1 amp / speaker. (maybe) the previous owner plugged the aftermarket directly into the speakers probably unplugging the bose amps at each speakers. Wich probably sounded like **** because of the impedance mismatch. There is also the possiblity that you have no bose speakers anymore, in wich case your head unit won't work. In theory a bose head unit could be connected to a proper amp to normal speakers, but i haven't heard anyone doing it.

I took one of the kickpanels off and the speaker was there along with the wiring harness. The harness was connected. Both rear speakers are also there and I do get some noise from them.

Are there any electronics with the speakers, or is the wiring just going to the head unit ? (Check for brand and impedance on the speaker too)

I took a kick panel back off to look again. The harness was connected. Do I actually need to open this up and take a look? I'm not sure what I'll see once I go further in.