Fog light isn’t working

[omarrrr239]

Hello everyone, this is first my first post my name is Omar.
I need help in why my fog light isn’t turning on in my 02 Yukon. I replaced the fuse, the relay and the switch. I checked if the harness is good by jumping wires and the lights turns on. The bulbs are good, I even replaced them. I check it the bulbs are getting power and no it’s not. I don’t have any ideas left in what to check. So I’m here to see if anyone knows what my problem is.
thank you
Omar

 

[OR VietVet]

Need to follow the wires from the light back and find the break. If you can find the wire with power to it and coming out of the cab, run a shunt from there if you want to. Are you talking about one light or both? Your info is not clear.

Welcome to the forum.

 

[omarrrr239]

Need to follow the wires from the light back and find the break. If you can find the wire with power to it and coming out of the cab, run a shunt from there if you want to. Are you talking about one light or both? Your info is not clear.

Welcome to the forum.

View attachment 348804

Both of the fog lights isn’t working. I’ll give it a shot In the morning and hopefully there’s a wire that is slice. Thank you

 

[omarrrr239]

Just out of no where the fog lights stopped working and it have brand new lights and fuse and relay and at this point I’m lost in what else to check

 

[Doubeleive]

does the high/low beam headlight? function, if high beam is on then no fog light

 

[Doubeleive]

also on the 02 you can simply ground the fog light ground to the frame and fog lights will work with high beam, the factory setting is to cut the ground to fog with with high beam on

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving great advice from the knowledgeable folks on this Forum. Check the ground wires going from the fog light bulb socket to ground, somewhere close by on the frame. These trucks are very sensitive to corroded grounds. If you have a multimeter, check for continuity between the ground contact in the fog light bulb socket and the truck's frame.

 

[omarrrr239]

does the high/low beam headlight? function, if high beam is on then no fog light

Yes both high and low beam works. I made sure if the high beam was off and it still doesn’t work. It’s only the fog lights doesn’t turn on

 

[omarrrr239]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving great advice from the knowledgeable folks on this Forum. Check the ground wires going from the fog light bulb socket to ground, somewhere close by on the frame. These trucks are very sensitive to corroded grounds. If you have a multimeter, check for continuity between the ground contact in the fog light bulb socket and the truck's frame.

 

[omarrrr239]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving great advice from the knowledgeable folks on this Forum. Check the ground wires going from the fog light bulb socket to ground, somewhere close by on the frame. These trucks are very sensitive to corroded grounds. If you have a multimeter, check for continuity between the ground contact in the fog light bulb socket and the truck's frame.

I don’t have a multimeter but in the morning I’ll go buy one and check out the socket and see if there’s a ground that isn’t connected. Thank you

 

[omarrrr239]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving great advice from the knowledgeable folks on this Forum. Check the ground wires going from the fog light bulb socket to ground, somewhere close by on the frame. These trucks are very sensitive to corroded grounds. If you have a multimeter, check for continuity between the ground contact in the fog light bulb socket and the truck's frame.

 

[Doubeleive]

does the light on the switch inside the vehicle light up when you press the button?

 

[omarrrr239]

does the light on the switch inside the vehicle light up when you press the button?

Like to button to turn them on? Yes it’s on whenever I turn the lights on. I’m not sure if I’m answering your question, let me know

 

[02Z71Raven]

Like to button to turn them on? Yes it’s on whenever I turn the lights on. I’m not sure if I’m answering your question, let me know

Specifically need to know if the LED that backlights the button that you press turns on.
There is a 10amp fuse in the panel in the side of your dash. I think it's for interior illumination. If you haven't checked ALL those fuses yet, I would stop and do that first.

 

[Doubeleive]

Like to button to turn them on? Yes it’s on whenever I turn the lights on. I’m not sure if I’m answering your question, let me know

the fog light button should not be lit unless you have the pressed the button first (key-on, low beam, or no headlights switched on), if the fog light button is lit always with key on then you have a short somewhere.

 

[Fless]

These should be listed in your owner's manual.

Underhood fuse and relay, verify fuse is good and has power on both sides, and swap the relay with a known good one (horn?).

In-cab relay / fuse center, verify power through #14 for backlighting as @02Z71Raven mentioned.

 

[omarrrr239]

Specifically need to know if the LED that backlights the button that you press turns on.
There is a 10amp fuse in the panel in the side of your dash. I think it's for interior illumination. If you haven't checked ALL those fuses yet, I would stop and do that first.

 

[omarrrr239]

This is what it looks like when the low beam is on.

 

[omarrrr239]

I check all the fuse and relay for the fog lights and still nothing I’m getting power from the switch but nothing to the relay under the hood. There’s something going on from behind the switch to the relay

 

[Doubeleive]

can't tell if that is lit up or not, when the plastic wears off it will show up as that blonde/natural color plastic underneath.
you stated that you replaced the switch already, does not appear to be the case based on your photo.
per your initial post.....
"I need help in why my fog light isn’t turning on in my 02 Yukon. I replaced the fuse, the relay and the switch"