Can I use a jumper wire to take the place of my foglight switch to eliminate the switch as the problem? The foglights on my 89 GTA quit working. Is there also a way to apply 12v at the relay to make sure that the lights can come on. This would help me track it down but I don't know where all the wires go and I'm not just going to start trying each one out and fry something. Does anybody have a wiring diagram for the foglights?

 

Can anyone tell me how to test fog light switch? Or at least what each wire is that connects to the switch?

 

I just posted a schematic in this thread, fogs on 91' GTA don't work, yesterday. Your '89 should be similar.

Checking the relay can be done at the socket with the relay unplugged, headlights on, and foglight switch on. If the switch is bad, there will be no battery voltage between the terminal C5 and ground.

HTH