I just bought a '89 F150 XLT w/ a 4.9L that has a fuel pump that continues to run with the engine off. the only way to make it stop is to disconnect the battery. Other than that, she runs and looks great. Any help would be appreciated.

 

pretty truck man, its clean.

and do you know any prior history on the truck? sounds like a bad connection from the ignition.

 

Unfortunately, nothing in the history corresponds to a fuel pump problem, or an ignition repair or problem. I assume that it's most likely electrical, but where do I start?

 

I think I got it fixed. I pulled the relay wiring clip off and the relay out to find out which one I needed (apparently there are 3 different ones). The parts store didn't have it, so I put the old relay back in. Problem solved. The relay either had some water get in and freeze, keeping the contacts energized, or there was a bit of crud in there. Either way, pulling the relay out and re-inserting it cleaned it out and now it works fine. One of the mechanics at Pep Boys told me that happens a lot, though usually it damages the relay and you have to replace it. Hope that helps anyone with the same problem. At least it's a starting place if the truck is drawing fuel the way it's supposed to, yet keeps running when shut down.

 

Thats a nice clean truck glad you got it fixed.

 

You could also use electrical cleaner and put a little electrical greese on the prongs to make sure they do not corrode in the future.

 

i just found your post and was wondering if you had any ideas that would work for my truck. i'm having the exact same problem with mine, except i think it's the starter that won't shut off without disconnecting the battery and i'm at a lost for what the problem could be. it's notthe stater, the switch, or the solenoid. i've got an 87 with inL6, 4.9L

 

Question IWS, why do you think its the starter. Does the engine continue to crank after the engine is turned off?

 

I had the same problem with the starter sticking. Don't think just because you bought a new solenoid that it isn't the problem. The parts store solenoids are junk. Remove the start wire from the solenoid while the starter is stuck. If the starter still keeps cranking then the solenoid is bad. Don't get one from the parts store, as I said they are junk. I went through 6 or 7 of them and finally went to the junkyard to get a factory part. Genuine Motorcraft solenoid and the problem was solved.