One day my fog lights quit working.

was talkin to my body guy one day and he said to pull it in and he'd test stuff for me. Well he put power into the relay and played around there and when he put power into the wires going from relay to lights they worked

...so he told me to replace the relay. I got one, plugged it in, same thing, no lights...I forgot about it for a while and figured
hell...why dont I just get a switch. Got a switch off ebay ( I know it COULD be a bad switch) but I plugged it in and they still dont work

So its not the lights, not the relay, not the switch, not any blown fuses in the box, harnesses look good, not any wires between relay and lights.......WHAT COULD IT BE

The only thing I could think of is maybe its the switch that tells the fog lights if the high beams are on, stock fog lights turn off when high beams are on...maybe it thinks my high beams are on, or is that all done in the relay.

 

With the running lights on, and the fog light switch on, try grounding the light green (high beam) wire at the relay. If the fog lights come on, then the ground path to the high beams is bad.

Does the fog light relay click when you turn the running lights on & off?

 

If I turn on the headlights/parking lights and hit the fog lights it does click.

So you say ground the grean wire and see what it does? I'll try it tonight and get back to you.

 

If the relay clicks, there is no need to ground the green wire. I'll take a look at the schematic & get back to you tomorrow.

 

I didnt see your last post till after I allready tested...so as you guessed it, it didnt do anything.

I pulled out the panels by the fuse box, all wires from switch to firewall look good too, this one really has me confused.

 

You will need a volt meter or test light to check the following. All voltage measurements are made with respect to chassis ground. The fog light relay has a red (battery power in from fusible link A at the large lug on the starter) wire that should have 12 volts to it, always. There is also a fusible link at the fog light relay on this wire. The brown (power to the fog light switch) wire from the fog light relay should have 12 volts to it when the running lights or head lights are turned on, but not when the high beams are turned on. The brown (power in from the fog light relay) wire at the fog light switch should function the same as the above brown wire at the fog light relay. The purple (power to the fog lights) wire at the fog light switch should have 12 volts to it if the brown wire has 12 volts to it and the fog light switch is turned on.

 

Well as you can see from the pic below...they work now!

But I still have some Questions. They didnt work cause when everything was off the red (constant) wire was only getting 7.72 volts, and when lights and switch or whatever was on it dropped to .04 volts. The other picture below is a new constant (little blue wire) I ran to it from the main fuse block for my sound system. Am I gonna blow something up. And also how could I find whats wrong with my factory constant. I cant find where it goes to.

 

If your head lights quit working when the fog lights were turned on then the problem is fusible link A or the power feed from it mounted at the large lug on the starter. If the head lights are OK, it's in the wire that branches off from the feed to the relay.