Car came with fog lights, but when it got to me they were missing. Found a decent set at the 'yard about a month ago, put them in, and nothin's working. The switch on the dash panel doesn't even light up. Fuse is fine, I know I got the wires right and all that stuff. Bulbs look fine, too. Any insight?

 

Insight?
Break out the voltmeter!
(or at least a test light)
You need to test voltage at the switch, the relay (on the inside of the driver-side fender) and the lights.

A repair manual with a diagram for your specific vehicle helps a lot. If you don't have one yet, it pays off fast to have one, they cost maybe $12.

Hope this helps.
Lou

 

I have a haynes manual that came with it, and its kinda helpful, but not very. It tells me the switch has a purple, yellow (or brown, mine has yellow), brown, and black... doesn't say anything about the gray wire next to the black one on the switch. It also told me all the wire colors that go to the relay, and I couldn't match up anything under the hood. I read voltage through the yellow and brown wires, and also through the purple and black, so I ran jumpers across yellow-brown and purple-black. When I ran them across yellow-brown, I tripped something that I haven't heard before somewhere in the dash, but still nothing came on. I did this all with the headlights on, so I know that I was getting full power to everything. I have a cluster of 3 relays next to the brake master cylinder on the firewall, is that what I'm looking for? I feel that the switch bad as when I tested voltage across the two contacts the yellow and brown wires match up to and flipped the switch, I didn't get any current flowing through. Still though, I feel like after running the jumper and guaranteeing current I would see some results. I'm at a loss.

 

You're right, Haynes isn't exactly perfect. But at least it's always a good start.

The grey wire is instrument illumination. It lights up the symbol in the switch.
The function of the other wires depends on how they wired up your car. And each manual describes it differently so I can't vouch for which way it's done actually.
And especially since I don't know the newer (90+) birds, I can't vouch for that either.

However, I might have some advice:
- look for the relay (small black cube, probably wrapped in tape) on the INSIDE of the driver side fender, by the battery or the winshield fluid bottle.
- the relay will MOST LIKELY (but not 100%) have different wire colors than what the manual says - look for: red/white, purple, brown/white and light green.

When you shorted the yellow to the brown, the click sound then must have been the relay. Which should be under the hood, though, not in the dash. Strange. Did the fog lights light up at that time? That would point to a bad switch.

If you find the relay and it does have red/white, brown/white, purple and green wires, then test the red/white, it's the main power feed from the fuse. It should be always hot (12V). The brown/white wire should be hot with lights on and fog light switch on.

Hope this helps.
Lou

 

Actually, with all the lights off, you can try to short the red/white to the brown/white on the relay (once you locate it) and that should turn on the fog lights.
If it does, you know that that part is good and need to look at the switch/dash wiring then.

Hope this helps.
Lou

 

Any update? Just curious if you found the culprit and what it was.

Lou

 

Yeah I actually ended up gettin everything working. I would have posted reply sooner, but I had finals and was at the beach, so I was kinda busy. The relay actually ended up being under the dash, not sure if thats how it always is for 91-92 but that's how it is on mine, was a Bosch relay. I forget exact colors on the relay but will check tomorrow. I went and bought new bulbs for the lights still had no luck, and it turns out that while tripping the relay I blew the fuse and didn't realize it (fuse was fine from the get-go, dismissed it for a while). Replaced fuse and bulbs and now have working fog lights, definetely sick as ****. Switch is still screwy though, light on dash doesn't turn on, nor does light on switch. If I have lights on for a while, turn off, and try to turn back on, the switch will not engage, will more or less not allow me to turn on (try to click on and will not stick, won't stay in on-position unless un-engaged for about a half hour). Still some bugs to work out, but they work when they do, so good times. I'll update with wire colors when I check it out tomorrow.