Neelskit

I have a 1983 F-250 2WD with a 7.5L motor- "hot fuel" dual fuel tanks. It's not getting any fuel to the carb- got it to run briefly today by rocking fuel tank selection switch back & forth- now neither fuel pump will kick on. Does anyone know where I can get a wiring diagram for this fuel system? Haynes was no help- no diagram for 7.5L with "hot fuel" option. I have ruled out the oil pressure switch, fuel pump relay, and inertia switch. The wiring starts to get quite messy at the selector switch. Trying to figure out if selector switch, relay, valve, or pumps are bad. Any help is greatly appreciated.

Thanks in advance!

ModMech

A 1983 7.5L was carbed and did NOT have any electric fuel pump, the pump was camshaft driven until 1986.

Neelskit

The fuel pump on the 1983 7.5L is mechanical UNLESS you have the "hot fuel" option, which replaces the mechanical pump with 2 low pressure (15 PSI) electric pumps, 1 in each fuel tank.

Arrowshooter

Neelskit: Did you ever figure this one out? Having same type of trouble with my 1989.

Neelskit

Sorry took so long to reply... Project (83 F-250) has been put on back burner for now- busy w/ work and other stuff, but I did narrow it down to an electrical problem under the frame. Everything checks out to the tank switching relays, fuel pump relay, inertia switch, and fuel diverter valve. Left off at checking wiring to the fuel pumps- either both pumps are bad -or- corroded wiring. Have you checked your inertia switch? (located on passenger floorboard) Ford seems to have issues with these switches in early model electric fuel delivery. Try bypassing the switch and see if you get anywhere... Good luck.

Arrowshooter

Actually noticed that none of the dash components came on until key was turned to start. Replaced ignition switch and all is fine. Thanks for the reply.