07 Yukon with bad fog light ground.

[Navy Dave]

My fog lights stopped working recently, both connections have power, but the grounds were bad on both. Fuse, relay, and bulbs are fine. Ground locations also fine. When inspecting the fuse box I used the handles and released the top of the fuse box, as I lifted up slightly on the fuse box the fog lights engaged and worked fine. I took off the top of the fuse box and cleaned the underside of it and the connectors that the fuse box connect to as it is inserted. Fog lights worked fine. Next day they won't work and the ground at the connections are bad again. So the problem is at the fuse box but I'm not sure if it is the top of the fuse box itself or the connections that it inserts into. I'm not sure which pin or wire at the fuse box would be the ground for the fog lights and how to go about it all from this point on.

 

[Doubeleive]

maybe @swathdiver has a diagram that could help
but if everything else is working and you don't want to hassle with it anymore then you can simply ground the fogs to the nearest ground point bumper, frame whatever.
won't hurt anything at all.
I have grounded aftermarket equipment. fogs and headlights like that for 20+ years on various vehicles, eliminates flickering and strain on the wiring.

 

[swathdiver]

My fog lights stopped working recently, both connections have power, but the grounds were bad on both. Fuse, relay, and bulbs are fine. Ground locations also fine. When inspecting the fuse box I used the handles and released the top of the fuse box, as I lifted up slightly on the fuse box the fog lights engaged and worked fine. I took off the top of the fuse box and cleaned the underside of it and the connectors that the fuse box connect to as it is inserted. Fog lights worked fine. Next day they won't work and the ground at the connections are bad again. So the problem is at the fuse box but I'm not sure if it is the top of the fuse box itself or the connections that it inserts into. I'm not sure which pin or wire at the fuse box would be the ground for the fog lights and how to go about it all from this point on.

 

[Navy Dave]

View attachment 402616

I know this much, I'm just trying to figure out which pin under the fuse box is the ground for the fog lights. I located the ground located on the front body mount and everything seemed OK there as far as the condition of the grounds.

 

[Doubeleive]

I know this much, I'm just trying to figure out which pin under the fuse box is the ground for the fog lights. I located the ground located on the front body mount and everything seemed OK there as far as the condition of the grounds.

pin 85 on the relay which will be directly under it, but if the lights worked when you lifted the fuse box it may or may not be the ground it could power as well

 

[Navy Dave]

pin 85 on the relay which will be directly under it, but if the lights worked when you lifted the fuse box it may or may not be the ground it could power as well

Power was good at both lights, the grounds on both were bad via a multimeter.

 

[Doubeleive]

Power was good at both lights, the grounds on both were bad via a multimeter.

ok, well in either case the pins are directly under the relay location under the fuse box, that part is easy. you can ohm test from there to the lights.