The General Motors Corporation (GMC) Envoy has technical service bulletins (TSB), recalls and complaints about the headlight socket problems. The headlight socket causes the bulbs to blow out, burn the wiring or even melt the terminals, according to many automobile review and report websites. The tail lights are also having similar problems as the headlight sockets.
The 2003 GMC Envoy has a recall from the manufacturer because of a headlight socket defect. The socket was manufactured at an angle deforming the shape of the socket. This defect causes the angle of the bulb to point away from the front of the Envoy, decreasing the illumination of the headlight. The headlights are dimmer than the applicable safety standards required. The defect can also cause the bulbs to blow out prematurely. The Envoy must be taken into a dealership to have new headlight sockets installed on the front of the GMC.
A TSB is published by the manufacturer about the headlight socket terminals melting on the GMC Envoy. According to Edmunds.com, the daytime running lamps (DRL) use the low-beam setting on the Envoy that run at a low voltage. The wires running into the terminal connections on the back of the headlight sockets are melting and burning because the voltage is running higher than specifications, causing the wires to get hot and burn. The only correction for this headlight socket problem on the Envoy is to have the wiring harness running to the headlight sockets to be replaced.
The Envoy is reported to have a problem with the light controls, which can run high and low beams simultaneously. When the headlights are turned on, the dimmer, low beam and high beam settings engage, causing the headlight socket to overheat and melting the contacts. These contacts can also melt to the bulb, causing the bulb to blow out. The Envoy owner can remove the bulb and visually inspect the headlight socket to see whether the contact points look burnt. If the sockets look burnt, the control switch inside the cab of the Envoy should be inspected to determine whether it is turning all settings on at the same time. The control switch needs to be replaced if this is the cause of the headlight socket problem.
