My fog lights, both front and rears, have stopped working. I did the dual rear fog light mod a while ago, and followed it up with the independant fog light mod (so I can run the fogs without having the headlights on) and everything was really good until about two months ago. Out of the blue, the lights wouldn't turn on sometimes, and then when they were on they would shut off after about half an hour of use. Now they don't turn on at all. I've checked my fuses and bulbs, so I suspect my relay(s) or the control module. I checked my solder joints on the control modules and (to my amazement) they are still solid. Is there any way to test relays with a multi-meter or some other magic? I plan on upgrading to HID (3000k) fogs but they kinda need to work, first!

 

Only way I can think of to check a relay would be with a test light. You have to have access to the wiring going to the connectors that plug into the relay's slots, and put a test light on the switched leg (the output) of the relay. With the button off, there should be no light. When you hit the button for the foglights, the test light should come on, indicating that the relay has latched and is able to send current out to the lights.

 

Does anyone have a relay layout diagram? I found them, and I don't want to just stop pulling them all, since I have no idea which one is for the fogs.

 

undo the soldering

 

The joints are still solid and you have to cut the pins off to do the mod, so that's not an option. All I need is a map of the relay locations so I know which one to test.