Hey, since I bought the car last fall the radio hasn't worked or worked very well. Problems Won't store channels or will store channels while the car is going and will lose them when the car is turned off The clock always starts at 0:50 for the time and then will count going up while driving. The radio station takes a while to pick up the channel, you might have to drive 15 mins or more before tuning in and when it does all known good channels will not work only some.
You have two power sources for radios, the constant, which keeps your presets on clock set, and then the one that supplies power only when the car is on or you have it in ACC mode, and that is the one that turns on your radio. Someone just posted the Fiero stock wiring diagram for the radio, and on most aftermarket stereos yellow is the constant, and Red is the ACC.
You're using a 12 volt probe light at the speaker terminals and GETTING 12 volts out of the wiring? I've never heard of that but then I have never tried that.
Did you use an adapter harness for the Fiero or just cut off the factory connector, meter the wiring and hooked it up that way?
This is from AndyLPhoto on here:
Be aware that some people have had issues with the taillight fuses blowing if you connect the gray (panel illumination) or brown (dim signal) wires so be careful.