There is no power going to the fuel pumps. We changed all the relays over and still nothing. If we ground the wire at the plug for the computer where you connect an obd reader to we get the pumps to turn on. What would cause this problem
My car has 101000 miles.
My car has an automatic transmission.
This is a tricky issue to diagnose without being there in person. It sounds like the pump may be getting a bad or weak ground. You will need a full wiring diagram and a knowledge of vehicle electronics and schematics to diagnose this. Start by checking power and ground for the pump at the relay terminals, and if you have power and ground, then jump the relay with a wire and see if the pump runs. If it doesn't, then it may be getting a weak ground somewhere else. Also check all the ground connections for the vehicle, especially ones along the frame of the truck, as these are often subjected to weather elements and may corrode, causing a bad connection. If this yields no results, I would have a qualified professional diagnose the loss of power at fuel pumps and help you move forward with repairs.
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