My guess? Fuel pump wiring. Check the connectors for the fuel pump back at the tank. I'd wager your old pump was fine as well. Check fuses? There are 2 fuses for the fuel pump. One under the hood, and one under the dash.

Isolate the fuel pump as a problem first. Pull out the fuel pump relay and jumper the two connectors so that the pump runs while the key is on. This bypasses the fuel pump circuit through the "start" position and the charge relay / alternator issues.

Truck off, key on, make sure you can hear the pump running when you put the jumper in. Wiggle the connector back there. It should not cut in and out.

If pump is running with the jumper and appears solid, try starting.

Jumper:




BTW, it appears the fuel pump relay has moved around depending on year and engine. The jumper is the same. Just make sure your jumpering the correct relay.

If the truck starts up and runs, try isolating the alternator. Put the fuel pump relay back in and pull and jumper the Charge relay. If truck still starts and runs, you've got a wiring issue in the alternator circuit.


--Dan