Help - 01 Tahoe fogs don't work . . .

[ypsetihw]

The lows and highs and turns work fine, but the fogs won't turn on. When I push the button inside the cabin, I can hear a clicking of a switch from near the electrical center under the hood, but the lights never actually come on. Yes, I did check the obvious and the bulbs don't appear to be burned out. Thoughts?

 

[amaz]

Fuses? You should first check voltage on bulb connector. If DMM says 0V, move to next connector (I believe it's under underhood fuse box). Next thing to check is the relay itself, there is atleast 3 same kind of relays in the underhood relay/fuse box that you can swap to check if thats the failing component.

 

[ypsetihw]

I have a voltmeter, any idea on the number or location of the relays I should test? What kind of readings am I looking for? Just testing continuity or is there a specified resistance? I'll also put the probes on the harness and see if its getting voltage down there or not with the switch in either state.

 

[amaz]

I have a voltmeter, any idea on the number or location of the relays I should test? What kind of readings am I looking for? Just testing continuity or is there a specified resistance? I'll also put the probes on the harness and see if its getting voltage down there or not with the switch in either state.

First, turn on your fog lights, test the voltage (DC V) from front fog light bulb connector (behind front bumber). If DMM displays ~0DCV, check the fuse and the relay.


You can see location of the fog lamp fuse and relay in the underhood fuse/relay box cover.