I just got a 2000 GMC Sierra from my brother. When ever you hit the brakes, the left turn signal lights come on, but don't blink. When you use the turn signals, it functions properly, even with the brakes applied. So it only acts up when I use just the brakes. My mechanic friend said there is a bad ground somewhere that I need to find. I'm extremely short on time as of lately due to moving and starting a new job, so if anyone can narrow down my search, I would greatly appreciate it. Thanks ahead of time, Mike.