2002 GMC Sonoma 6 cyl Four Wheel Drive Automatic 150000 miles
my truck died on me the other day, I thought it was the fuel pump but I took the fuel pump out and hooked it up to a car battary and it works fine but when I plug it in to the truck it dosent have power iv check everything but the relay because I have know idea where it is, but I dont know if thats it anyway
A no load test on a fuel pump isn't worth much. I've seen faulty pumps that would run laying on the bench, but, when you put a load on it, you get nothing.
If you tested the gray wire at the fuel pump connector, engine cranking, and no voltage, your correct, check the relay in the power distribution center, under the hood. Ecm B fuse supplies voltage to load side of relay. The control/coil side of relay also gets voltage from the pcm. Not sure of actual voltage supplied to that circuit, use digital multimeter if testing.