I replaced the electric fuel pump in my 1991 Ford Explorer 4x4 4.0L about three months ago.
The other day I noticed that the fuel pump is continuing to run "AFTER" the truck is shut off.
I went to Auto Zone and was told it was the fuel pump relay. Before I unhooked the battery I started to wiggle the fuel pump relay and every now and then the pump would shut off. I assumed this relay was the problem. I replaced the fuel pump relay and as soon as I hooked the battery up.......the fuel pump began to run...the truck was shut off.
I then went back to Auto Zone and was told it was the starter switch/relay located under the dashboard......he stated that when I shut off the truck, the switch/relay was not getting a good contact. So I bought and replaced the starter switch/relay. Again, as soon as I hooked up the battery, the fuel pump began to run while the truck was shut off.
I thought the fuel pump I bought was no good but the guy at the parts store told me that the pump itself does not turn itself on and off and that the pump relay or starter switch/relay does that.......he had nothing more to tell me about this problem.
I would be greatful if someone could help me with this problem.
Thank you
Eric
em685(No Email Addresses In Posts!)

 

I changed out the relay closest to the firewall but still had the problem of the fuel pump running when the truck was shut off.
The relay I replaced was crossed checked at auto zone and found to be the fuel pump relay.
I then, for some reason, pulled off the relay closest to the front of the truck and seen that the prongs looked different from the one I replaced, so I hooked that back up.
I then, pulled off the middle relay and noticed that the prongs looked the same as the relay I replaced.......so I hooked the old relay back up where it was at to begin with, and put the new relay in the middle and the problem is fixed.
I hope that this will somehow help anyone who might run into this problem down the line......
Eric