Tech Tips (by ALLDATA): GMC Envoy stalls when using left turn signal
TECH TIPS (courtesy of ALLDATA)
Problem: The vehicle stalled only when activating the left turn signal. The customer also noticed that the left headlight was dim. The customer replaced the headlight but there was no change. The stalling problem began to get progressively worse until it happened constantly.
Details: The technician found only 2.0 volts on the ground circuit of the headlight and the left turn signal. Both components were grounded at the same location (G107), which is located on the engine block. Although the ground looked good and tight, the bolt was corroded and a little rusty. The wiring diagram showed that the fuel pump relay was also grounded at the location.
Confirmed Repair: The technician wire-brushed the contact point on the engine block and replaced the bolt and washer. The headlight was now bright and the stalling problem with the left turn signal was also resolved.