My truck had a habit of deciding not to run during extended rainy periods, and sometimes after a trip to the car wash. Analysis of data available via Torque OBD made it clear the fuel pump wasn't running.

My suspicion was that corrosion at the fuel tank connections was the culprit. After a few tows home (thank goodness for AAA!), I found time to investigate more fully.

While dropping the fuel tank (ugh!) I was stuck trying to disconnect the wiring from the tank. Couldn't figure out how to release the latch on the connector.

While searching YouTube for answers, I came across a video of a guy fixing his friend's F150 by replacing the fuel pump driver module. Before seeing this video, I had no idea such a thing existed! It lives on the frame crossmember at the front edge of the spare tire, just behind the evaporative emission control canister.

After cutting down the spare tire - the winch was rusted solod - I found the very sorry looking fuel pump driver module. It was already cracked, which I am sure admitted sufficient moisture to cause malfunctions. The housing was so corroded that a light tap with a screwdriver opened up a hole in the back.

I just finished the job today, so I can't say for a fact that the problem is gone, but I have a high level of confidence that it is.

The replacement Dorman part came with standoffs so that corrosion doesn't develop between the module and the frame crossmember to which it is mounted.


Replacement module in place.

 

Looks easy. Is it really just unclipping the wire harness, and 2 bolts?

 

Very common issue. Be advised, the Dorman replacements have a high failure rate. The Motorcraft replacements also come with standoffs now.

 

Yes, once the spare tire is removed. You might the able to do it with the spare in place, but it will be more difficult.

My spare tire winch was rusted solid, so it took some work with an angle grinder to get the spare free.

 

In that position, you would think that the spare tire would have protected it from any water splashing up.

Nice to see that the harness was not corroded. Sure, you could splice a new harness on. Just a real pain to do things in that position. I envy guys who have a lift. I have to do everything crawling under the truck, laying on my back. Even changing the differential fluid is a pain in the a**.

 

Not really. even with the spare in place, it is exposed to spray from the left rear wheel. I disabled the truck once by being aggressive with the spray wand at a car wash in that particular area.

 

I will have to keep that in mind. Some of the drive through car wash machines have water spraying up as you drive in. Suppose to clean the underbody. I'll be especially mindful when doing a quick spray in the driveway wash. My car wash at home technique uses one of those spray nozzles with a reservoir for soap. I buy the inexpensive Turtle Wax or Armor All brands that allegedly have wax mixed in. So I spray water to wet. Spray soap mix. Allow soap to sit and penetrate dirt. Then rinse. Not the best car wash. But better than nothing. And it gets quite a bit off the truck. Just too lazy to climb a ladder to hand wash, clay bar, & wax. Cutting back on the $14 drive through machine washes. Refuse to spend $100 for hand wash, clay bar, and wax.

 

Wow, I was so lucky …. back in like 2010 or 2011, just got home from a 1000 plus mile trip to visit family over Christmas, read my first thread on failed FPDMs and just dropped my spare to look. FPDM was some corroded on back or frame side, but a wire pricked my finger, some rodent had chewed on it ….. I REMOVED FPDM, cleaned it, clear coated it heavily, remounted with my own spacers to stand off, and fixed wiring. One wire was only hanging on by one strand. I spliced in new wires, solder, shrink wrapped and thanked my stars for me reading that thread.

I still check it now and then. Had a rodent also once chew into fuel line and fixed. I hate tows, try to avoid them.

 

I hope that rodent lost his footing when you hit a pothole at highway speeds.