Troubleshooting Driver Side Low Beam Headlight Not Working On A 2005 GMC Yukon Denali  

Question:

Expert Reply:

The first thing you should check for is the fuse that provides power to your driver side low beam headlight. This is a 10 Amp fuse labeled "LO HDLP LT" and will only have power when your headlights are turned on.

Additionally, the HDLP LO RELAY controls both headlights when they are on low, so if one light works on low this means that the HDLP LO RELAY is working properly.

Next, you'll want to check for power at the low beam headlight socket on the yellow wire, remember to turn your headlights on.

Finally, you'll want to check your ground connection, the black wire on the headlight socket is the ground. You can do this by using a circuit tester like the circuit tester # PTW2993. Start by clipping the clip end to the black terminal on the headlight socket and taking the pick end (sharp end) and touching the positive side of your vehicle's battery. If it fails again trace the black wire and see where the ground is interrupted.

expert reply by: Bryce D

0

Fuse, and relay locations.
(click to enlarge)