On my old car I put in my Pioneer Supertuner head unit and after I did that my headlights and stereo would not work at the same time and I had no dashlights, and before I did the swap everything was fine. I am getting ready to put the head unit in my 90 but before I do I want to know if anybody knows what I did wrong on the last one?
Also I got an amp from this kid for like $10 it is a Rockford Fosgate 4.6X 300 watt amp, does anybody know if it isa good amp or anything like that?

 

sounds like you grounded the dimmer or illumination(orange) wires to the dimmer ground(orange and white). This is a simple mistake and When you do this you short out the dimmercircuit, and probably blow a fuse in the dash. Now if you were smart you recognized that something waswrong to blow that fuse, and do not put a larger fuse in its place. The last time I heard of someone making those two simple mistakes, they burned the illimination wire from behind the radio where they shorted it, to the fuse box where they had worked up to a 40amp fuse before the wire caught fire(I do mean fire!). It meltedthe ignition hrns and a few other things that the dealership totaledup to $3500 worth of damage before they could even consider putting another radio in.............

The dimmer and the dimmer ground are not as similar as they sound....