Hello,
Have a 95 Ford that I bought, not running, but real clean and straight. Been sitting up for a year or so. Cannot get any action out of either fuel pump. Tried grounding the pumps through the diagnostic link, but nothing. Checked all of fuses, nothing. Cleaned the ground cable behind the battery, and cleaned the one on the LH side of the radiator support, which is shown to be the ground for the pumps. Can't get any power to the tank switch either. This is the 3rd truck, all F150's, 93--94-95, and its apparently the same problem. The only written material I have is a Chilton manual, which is about one notch above "Dick and Jane". I also checked the inertia switch, but the "manual" does not make it clear what position the button should be in, up or down. Have tested for power, both ways, and at this point, it doesn't matter. I realize I am dealing with this computerized "space age" machinery, to put it politely, but surely there must be a way to properly troubleshoot this particular part of the system. Any help would be greatly appreciated.

Thanks

 

Button should be pushed in (down) have you checked the relay? and the hot wire at the relay? mine was all green and broken off there. this happened on a couple of my F 250's

 

When you ground this point you have bypassed the computerized "space age" machinery.
This is a very simply circuit once you ground that point (pin #6 of the diagnostic link).
The fuel pump relay should click when you ground it and click again when you remove the ground with the key on.
If it does not check to see if the PCM power relay is clicking when you turn on the key.
Do you need a diagram?
If so email me.

 

Hey guys,
Thanks so much for the info. Just a couple of dumb questions - when you say "relay", where, exactly, is the location of this? And yes, when you ground out the pumps, I can hear a relay click, but still no power to the pumps. I can't believe that out of 3 trucks and 6 pumps, that they are all bad.......

 

Relay is on driverside wheel well, under the hood, marked "FUEL PUMP RELAY", it's a square black box looking thing, you can't miss it.... (Thats where it is on my 91 F150, anyway.....)

 

The relays:

 

Oh man!!!! They say a picture is worth a thousand words ! So true, so true! Thanks so much. Now, are these relays prone to failure fairly often? And, for test purposes, can you interchange the fuel pump relay with, say, the horn relay, just to verify if it's the problem ? Or, do you have to have a new relay specifically for the fuel pumps? Now that I'm on the same page with ya'll, what's my next move ? You don't know how much I appreciate ya'll's help.

Thanks,
John

 

They can and do get replaced a lot but I do think they have failure very often.Yes you can.No they are the same. Check for power at the fuel pump supply fuse with a test light (never use a meter in this circuit it will lie to you) at the little silver places on both side of the fuse with out taking it out.
If good swap the the relay with the horn relay and toot the horn.
If the fuel pump relay clicks when you ground pin #6 of the test connector with the key on then the PCM power relay is OK.
As you can see in the diagram below if you have power at the fuel pump supply fuse and the fuel pump relay clicks when you ground pin #6 there is only a wire between the fuel pump relay and the Inertia switch.
Let me know what you find.

 

hey subford I’m having a similar issue truck was sitting for a year or two. Not getting any ground to power the fuel pump. Test lighted everything all fuses are good but no power to the pump. I have a single tank straight 6 f150 1995 manual and can’t seem to get the pump to turn on. I bought a new one but also can’t get the tank dropped because the bolts are locked and stripped and rusted trying to get it running so that I can start fixing it up and drive it but no fuel comming through the system.

 

I am having same problem . But I have no power to any relays. Truck turns over and the dash works but not ac or heater fan