Here it goes i have a 1986 fiero se

i got it last year well my dad got it, and it came with a good cassete player detachable face and after a couple months of listing to it, it stopped working it wouldnt turn on?? And i accedintly lost the face so i took out the radio. Then yesterday i bought a new jvc cd player from sears, and i bought a harness and wired it up correctly and i plug it all in and it doesnt turn on?? I checked the fuses and they are not burned out? I dont know what the problem is could it be electrical, also do i have an amp in my car built in i have a performance sound switch by my dome light inside... please reply.

Yes, it's electrical.
Run the 'HOT' wire for power to the radio back to the fuse box. The previous owner may have put an in-line fuse in it somewhere.
If (and I'm sure it does)have a built in memory circut make sure there is power there as well.
One of the yellow wires should have 12 volts ignition on and acc. positions.
The orange wire should have 12 volts all the time, this should be used for your memory. Battery fuse in the fuse block feeds the lighter, horn relay courtesy lights and memory, check it!
Thr brown wire goes to the light dimming circut.

I covered some of the stuff about the OE radio in my cave. That might help you figure out what wire is what. "memory" power is on a seperate connector from the main radio connector.

Well guys i found out the problem!!!!!

the mem wire was dead so the player wouldnt turn on. So i spliced it with the yellow wire and it works fine

Sounds like your all set to operate. Too bad it won't keep presets that way!

I have a similar question. My new stereo has a wire for illumination/dimmer. What wire from the car should I use for this? I'd like to have the radio automatically dim when I turn the lights on. Is there an alternate way of doing this without using the stock wiring?

I am not positive but if I remember right it is the Gray wire