Fuel Pump Stays on

[T-Doe]

After my 90 ranger turns off my fuel pump stays on the less distance or time it is running the longer the pump stays on and sometimes the whole pump stays on. It's killed my battery before has anyone had this problem?

 

[Southern3.0]

I used to have the same exact problem with my '91 ranger. Never figured it out, I posted the subject a few times and all anyone could do was scratch there head. I stared at wiring digrams for hrs, probed at wires, replaced relays, nothing. i ened up just wiring in a separate relay in the fuel pump curict that would send power to the pump any time the radio had power.

 

[Sasquatch_Ryda]

I had a Focus at work that killed the battery overnight and then when jumped wouldn't start. Fuel pump was the problem.

 

[sbsrlewis]

Same problem with 89 BII with 92 4.0 from Explorer. Had one mechanic tell me to replace relays with ONLY Ford relays. That worked for a while but then it was back to running at all times. I just ended up running the power wire for the pump thru a stock fog light switch on the dash. Now I have to "turn the fog lights on" to start the truck. The pump only runs when I want it to now and it's also a theft deterant now.

Good luck.

Steve

 

[289-tiger-]

Bad ignition switch?

 

[shadetree]

After my 90 ranger turns off my fuel pump stays on the less distance or time it is running the longer the pump stays on and sometimes the whole pump stays on. It's killed my battery before has anyone had this problem?

I'm not really following what you are saying. When you turn the ignition off, does the truck keep running, or just the fuel pump?

Distance/time the longer the pump stays on??

"The whole pump stays on?" ????? What does that mean?

Have you swapped the fuel pump relay with one of the other relays? Try that.

If that doesn't fix it, the power wire to the pump has shorted to another wire in the system. You will have to trace the wiring back to the pump to find out which one. Start at the fuse box and the relays. Look underneath the box at the wiring. shady

 

[sbsrlewis]

Distance/time the pump stays on? As long as the battery holds out.

"The whole pump stays on?" ????? The pump will continue to run until the battery dies or I remove the relay.

Have you swapped the fuel pump relay with one of the other relays? Yes. I purchased 3 new relays from O'Reilly and that fixed it for a day or so. Then I purchased 3 new ones from NAPA and that worked for a while. Since then I have bought 6 from the Ford dealer. The ones from Ford solved the problem for a couple of weeks and then it was back to the same again.

Like I mentioned in my above post I finally put a fog light switch in the power wire so I can turn the pump off when I turn the key off. I have also removed the relay all together and now just have a jumper wire in its place. Works great now (as long as I remember to turn the switch on/off when needed).

Power wire to the pump has shorted to another wire in the system. You will have to trace the wiring back to the pump to find out which one. Start at the fuse box and the relays. Look underneath the box at the wiring. Done that too and didn't find anything.

Steve

 

[T-Doe]

I'm not really following what you are saying. When you turn the ignition off, does the truck keep running, or just the fuel pump?

Distance/time the longer the pump stays on??

"The whole pump stays on?" ????? What does that mean?

Have you swapped the fuel pump relay with one of the other relays? Try that.

If that doesn't fix it, the power wire to the pump has shorted to another wire in the system. You will have to trace the wiring back to the pump to find out which one. Start at the fuse box and the relays. Look underneath the box at the wiring. shady

When i turn the ignition off the fuel pump keeps running

the less the engine is running the longer the fuel pump will stay on sometimes it runs until the battery dies

i meant sometimes the pump doesn't stop running i don't know how i managed what i typed

i'm gonna just hook up a toggle switch to it and make sure i turn it on and off

 

[almostclueless]

A good wiring diagram will show the wire that triggers the relay. If it has voltage when the key is off replacing relays probably won't fix it.

 

[Bob Ayers]

Distance/time the pump stays on? As long as the battery holds out.

"The whole pump stays on?" ????? The pump will continue to run until the battery dies or I remove the relay.

Have you swapped the fuel pump relay with one of the other relays? Yes. I purchased 3 new relays from O'Reilly and that fixed it for a day or so. Then I purchased 3 new ones from NAPA and that worked for a while. Since then I have bought 6 from the Ford dealer. The ones from Ford solved the problem for a couple of weeks and then it was back to the same again.

Like I mentioned in my above post I finally put a fog light switch in the power wire so I can turn the pump off when I turn the key off. I have also removed the relay all together and now just have a jumper wire in its place. Works great now (as long as I remember to turn the switch on/off when needed).

Power wire to the pump has shorted to another wire in the system. You will have to trace the wiring back to the pump to find out which one. Start at the fuse box and the relays. Look underneath the box at the wiring. Done that too and didn't find anything.

Steve

If changing the relay works for awhile, then something is fusing the relay N/O contacts shut. Normally, excessive current will do this. A bad fuel pump can pull too much current. I suggest measuring the current the pump is pulling.

 

[Earl43P]

I like this test http://www.tomco-inc.com/Tech_Tips/ttt23.pdf Page 2

Sounds familiar to your issue. Why else would your relays keep welding their contacts? High current. Gotta be either a bad relay (yeah, something keeps frying them), poor connection, a poor ground, a bad fuel pump, clogged sock, etc.

Have you jiggled the bejesus out of the ignition switch while the pump is running with the engine turned off?