Low Beam Not Working

[Jastacey]

I believe this may have been covered .... but I'll ask anyways, I have a 2002 Yukon XL 192K miles and the low beams started to not work

What I've done is, I pulled the passenger light bulb off the assembly and checked to see if I have power to the bulb, ( I put the parking brake on, and turned the dash switch to the 12:00 noon/on position ), I'm getting 12.50 volts on the orange wire, but when I checked for negative continuity on the yellow, there is none, I checked the dash switch and there are a green & black wire and they test good for ground continuity, could it be the switch? or could it be a ground connection between the engine compartment and the dash, the Multi-function switch seems to work fine .... I just don't want to throw parts at this issue

I swapped the relays in the engine compartment fuse box, but that had no affect on the low beams

 

[08grey]

Switch cycles power on and off ground should be constant. If ground is missing there is a bad connection on the ground somewhere. Probably just corrosion. Peel back some insulation on the ground Ground a wire and splice it onto it and you will have a shade tree mechanic fix.

 

[Jastacey]

Well, here's an update, I traced the ground wire from the battery, that goes to the frame, under/near the battery, and cleaned the bolt/washer & wire connectors, and re-tighten them, and the low beams came on ( had the parking brake set, I'm assuming that turns off the daylight senser ), when I tried to do it again 2-3 minutes later, the low beams didn't come on, although the high beams do come on ... still looking for additional ground locations


Well ..... after fiddling around trying to find the iffy ground/grounds, I just decided to run a ground wire from the yellow wire ( Driver side low beam to the grounding terminal that I cleaned up earlier ( under the battery/front crossbeam behind the bumper) and both low beams lite up, I'll run another ground wire from the passenger side low beam to another grounding point, that way I'll spread the load, and each light will have a seperate ground .... it may seem a bit unorthodox, but it works and I didn't spend/waste dollars on switches/relays/etc. hope this helps someone else

 

[sumo]

moved to proper location