This 2004 GMC Envoy came in with the passenger side low beam not working. This repair applies generally to Envoys, Bravadas and Trailblazers, with only slight differences in the headlight assembly removal. Some require removing the grill assembly. This one is pretty simple though. Pull the retainers straight up. You can use just you fingers. If you decide to use a screw driver for leverage, be careful not to break anything.
Pull the second retainer up.
With the retaining bars released the headlight assembly can be gently wiggled out to expose the wiring. The light sockets twist and rotate out. The larger socket has a lever lock that has to be depressed before removal.
There is another harness connector at the lower inside edge that has to be removed.
With the assembly out of the vehicle , I removed the rubber cup covering the light bulb and wiring. Looks a little toasty.
Rotate the bulb counter clockwise and remove.
This is the replacement harness connector that I like to use. It is a high quality German connector that has been modified to fit this application. To order this low beam repair harness please click here. If you need a high beam repair harness please click here.
A couple of quick splices.
Splices done with heat shrink tubing in place.
Connect the harness to the bulb. Do not touch the glass on the bulb. The bulb will blow after installation if any oils from you hand attaches to the glass. The oil causes uneven heating of the glass and it will shatter and let the inert gas out and then the element will burn out.
Using the harness connector as a handle insert the bulb back into the headlight assembly and twist into place. Install the rubber cover and install in the vehicle. It’s that simple.
Power for the low beam headlight on the left side is supplied on the yellow wire (terminal”B”) at the headlight external connector. It is powered from fuse #6 in the underhood fuse box. Should be labelled Low HDLP-LT. It will only have power on it with the headlights on and low beam selected. If the fuse is good and has power on it then there is an open circuit between that fuse and the headlight connector. Ground for that low beam headlight is supplied on terminal”D”, black wire of the external harness connector.
2004 GMC Envoy Driver lft Low Beam inoperable. Checked bulb visually and with ohm meter-good. replaced socket and two wire harness. checked voltage on 4-prong lead to light housing and only get voltage on obe prong. Swapped relays 45 and 46 I think and fuse 3 & 6. Rt continues to work still no low beam on lft side. brights and flasher work but no low-beam.
I have some questions for you so maybe we can work through your problem. Did you install a brand new bulb and connector at the same time? Did you use a standard factory rated bulb, good name brand? How long did it take for the issue to return, hours, days, weeks? Where did you get the connector from? Any chance you took a picture?
Good information, unfortunately when I preformed this repair the replacement “heavy duty” connector I put in melted as well.
thanks,i was going crazy trying to figure out how to change bulb on headlight but with your instructions it was simple. thanks