1990 Ford E-Series Van V8 Two Wheel Drive Automatic 150, 00 miles
1990 E250 cargo van, 302 c.I. Engine, dual fuel tanks.
Replaced alternator, regulator, fuel pump relay & removed defective " inertia fuel cutoff switch", connecting the 2 wires that ran to it. Removed high-pressure fuel pump & tested - it's good.
Van ran fine for a while, then quit as if it ran out of gas (both tanks over 1/2 full). Replaced fuel pump relay again, test from EEC self-test #6 to ground says it's working, but no voltage is getting to the pumps. Continuity test @ different places in the wiring says the wiring is OK - can't find anything else between the relay & the main fuel pump which would stop voltage from reaching the pump & going on back to the pumps in the tanks.
The schematic in a Haynes manual is poor as it doesn't cover the whole system or all the relays/switches in it, but further trial & error testing revealed the EEC relay had gone bad too & that was keeping power from going to the fuel pump, even though the fuel pump relay was good (new).