Fuel Pump runs with key out of ignition

[Christobal65]

I just finished replacing the fuel pump relay because after searching It was indicated that the fuel pump relay was bad. So now im looking for other ideas as to what is causing the fuel pump to run.

 

[MrShorty]

Need to go through the wiring a little more carefully. A short to ground in the wire that goes from the relay to the PCM could cause the fuel pump to run continuously if the EEc relay were also stuck closed. Do you have a wiring diagram? Even the ones in Chiltons or in the vehicle repair guides at autozone.com are better than nothing.

 

[Christobal65]

No i dont have any repair manual or wiring diagrams, i've always just used this site when i needed help lol.

 

[unclemeat]

Did you use a motorcraft relay? I bought one at Advance and it did not work properly. Replaced it with Motorcraft and it worked right.

 

[DeRocha]

Until you get things sorted out you can unplug the wire connector on the inertia switch to kill power to the fuel pump...

 

[Four0Sport]

the wonderful inertia switch.. its almost like they knew these vehicles would roll over and thought 'hey.. at least we can turn the fuel pump off for them so they dont die in a raging fire ball' ive actually never had problems with the inertia switch, although it gets blamed for alot of problems. good idea on a way to disconnect power to the pump in the cab!

 

[DeRocha]

the wonderful inertia switch.. its almost like they knew these vehicles would roll over and thought 'hey.. at least we can turn the fuel pump off for them so they dont die in a raging fire ball' ive actually never had problems with the inertia switch, although it gets blamed for alot of problems. good idea on a way to disconnect power to the pump in the cab!

Back in the day I installed a fuel pump kill switch...

See Post #20+ of the kill switch thread

 

[Willard]

Freaking intertia switch, I've never had problems with mine per say, but when I got in my wreck (tree at around 30mph) I had to shut the motor off because it didn't.

On the problem at hand, it either has to be a wiring issue triggering the relay constantly, or the relay itself is wrong or just faulty. For the price of one, I would be tempted to try that first. Or try another relay from something else (I believe the blower motor relay will work?)

 

[H munster]

Just for troubleshooting purposes, but is there still power to anything else that shouldnt be with the key removed?

 

[Christobal65]

Did you use a motorcraft relay? I bought one at Advance and it did not work properly. Replaced it with Motorcraft and it worked right.

Yeah in my searching i ran across a thread that said to stay away from other brands so we ordered it from ford.

Until you get things sorted out you can unplug the wire connector on the inertia switch to kill power to the fuel pump...

where exactly is this inerta switch in the cabin?

On the problem at hand, it either has to be a wiring issue triggering the relay constantly, or the relay itself is wrong or just faulty. For the price of one, I would be tempted to try that first. Or try another relay from something else (I believe the blower motor relay will work?)

I thought about that too, because when i put the new one in it was fine till i turned the ignition switch on. As soon as i hit the ignition it came on and stayed on again.

Just for troubleshooting purposes, but is there still power to anything else that shouldnt be with the key removed?

Not that i know of, everything esle shuts off like normal.


Also just so you guys have more info to work with it will start normally once i reconnect the battery (the fp comes on right when i connect the battery) but if i let the pump run for too long it will just crank and not start for a while.

 

[DeRocha]

...where exactly is this inerta switch in the cabin?

The inertia switch is located under the glove box, behind the carpet..