One problem related to wiring has been reported for the 2012 GMC Terrain. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2012 GMC Terrain based on all problems reported for the 2012 Terrain.
The low beam h11 bulb is causing the (male/female plug in) for this component to overheat causing the plastic to become charred, partially melted and brittle in which the low beam light stops working due to this problem. The wiring is becoming soft at the plug in connection from this heat and allowing the protective wire insulation to be melted permitting the bare wire to be visible which could produce a fire hazard at this location. This has occurred on the right side twice and on the left side once. In all three cases, the bulbs with the female plug in and the male electrical connection has been replace. This vehicle has only 28755 miles on it. Just noticed the low beam light on right side not working again today. Replaced this side within the last 9 months.