Redoing all my lighting. My fog lights have never worked. So far I've replaced the bulbs, fog light relay, and checked the fuse for the fog lights. So the fog light switch has power (checked with a volt meter), the relay has power. I have a wiring diagram pulled up and other than the fog light switch itself being bad I can't see what else would be causing the problem. I tried using a temporary universal 2 prong switch hooked up to the fog light switch terminal but that didn't work. I'm out of ideas. I have a fog light switch on order (its a used switch).

 

You said that you have 12v+ at the Fog-Lamp Switch.
Are you saying that you have 12v+ at the Power-In Terminal?
...or are you saying that you have 12v+ at the Power-Out Terminal, when the Switch is ON?

The Fog-Lamp Circuit design is rather crude, compared to more modern Circuit designs.
The Fog-Lamp Switch (a high Amperage Switch) actually carries/ passes the Amperage demands of the Fog-Lights.

The Fog-Lamp Relay only acts as a control device, to determine when the Fog-Lights can turn ON.
For example; the Fog-Lights can only turn on if the Head-Lamp Switch is ON...
and the Fog-Lights can NOT turn ON if the High-Beam Head-Lights are ON.

Below is a Schematic for a 1986 Camaro:



If there is 12v+ at the Power-In Terminal, but NOT 12v+ at the Power-Out Terminal, when the Switch is ON...
The Fog-Light Switch is not operating properly.

If there is 12v+ at the Power-Out Terminal, when the Switch is ON...
But there is NO 12v+ at the positive Terminals of the Fog-Lights...
Then there is a damaged Wire/ open Circuit in the 16AWG Purple Wire between the Fog-Light Switch, and the Fog-Lights.

If there is 12v+ at the Power-Out Terminal, when the Switch is ON...
And there is 12v+ at the positive Terminals of the Fog-Lights...
Then there may NOT be 12v- (Ground) at the negative Terminals of the Fog-Lights.

If there is 12v+ at the positive Terminals of the Fog-Lights...
And there is 12v- at the negative Terminals of the Fog-Lights...
Then the Fog-Lights/ Bulbs would NOT be operating properly.

 

So as I was going to double check power at the relay and switch my fog lights lit up. Looks like the relay connector itself is just worn out and needs to be replaced. As I was moving it around when the lights turned on.

 

Well that is good news.


However, something does not make sense...
You said that the Fog-Light Switch had 12v+ at one of the Terminals (hopefully the Power-In Terminal: 16AWG Brown Wire).

If the Fog-Light Relay was inoperable, or operating improperly...
None of the Fog-Light Switch-Terminals should have 12v+, except for the Terminal for Back-Lighting: 20AWG Grey Wire (ONLY with Head-Light Switch ON).

 

When I checked for power the first time I had the relay unplugged (as it was bad and I hadn't been to the store yet) and was probing the relay connector with the fog light switch on. And when I checked for power at the fog light switch (New relay was installed at this time) I had it unplugged and was probing the connector terminal.

Edit: is the wiring diagram you posted for an Iroc? Or does it not make a difference?

This was the wiring diagram I was looking at.
http://austinthirdgen.org/mkportal/m...ody_wiring.gif

 

Your Schematic is for a FireBird.

Notice that, there are only Two Head-Lamps (instead of Four), and there are Head-Lamp Motors to raise-up/ flip-up the Head-Lamps.

My Schematic is from an actual/ GM OEM, 1986 Camaro Technician's Manual.

 

I have no idea how I missed that was a Firebird wiring diagram. Won't make that mistake again. lol

 

Thats okay.

No one is perfect... I certainly am not perfect.

The majority of People here are Car Enthusiast, and not Professionals.
I really love these old cars (Third-Gen F-Bodies), that we here all own...
Since I am a Professional, I like to try and "Give Back" to other Third-Gen Owners/ Forum Members.