GMC Troubleshooting Questions? Ask a Mechanic for Answers
hello, my name is ***** ***** I will be glad to assist you. please allow me a couple of minutes to gather some basic info.Roy
I attached a wire diagram for you to view.
check for power to the glow plugs with a test light. if you do not chances are the controller is bad but you need to verify the powers to it.
one other thing, if you find any the controller bad, replace all glow plugs. that was the reason for the controller failure