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EricFromCT, Ford Technician
Category: Ford
Satisfied Customers: 3959
Experience:  20 years dealership exp., ASE A1-A9 L1 L2, Ford Lincoln Mercury Senior Master, Diesel Certified
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Ford F-150: Have a 2005 F-150. With the key out of the truck

Customer Question

Have a 2005 F-150. With the key out of the truck the fuel pump continues to run until the battery goes dead. Have read where the fuel pump relay could be the problem but there is no relay for the fuel pump listed in the owner's manual. Tried to jump start in order to charge the battery, but engine would not turn over.
Submitted: 2 years ago.
Category: Ford
Expert:  EricFromCT replied 2 years ago.
Hi. My name is ***** ***** I will assist you with your concern today. Please rate my assistance after we have concluded chatting.
What engine is in your truck? Thanks.
Customer: replied 2 years ago.
4.6 L
Expert:  EricFromCT replied 2 years ago.
Ok. Your truck has a fuel pump driver module. It is located above the spare tire mounted to the frame. This module is what controls the fuel pump. It is very common to go bad and even rot out to the point where the circuit board is fully exposed. What I would recommend first is to visually inspect this module for signs of damage. Then let me know what you find. Thanks.
Customer: replied 2 years ago.
Ok, I will check that out.
Expert:  EricFromCT replied 2 years ago.
Ok. Sounds good.
Customer: replied 2 years ago.
I unplugged the module and removed it from the frame. I don't see any broken wires or signs of damage to the module itself. On a hunch, I hooked the battery back up without the key in the ignition. With the module unplugged the pump continues to run.
Expert:  EricFromCT replied 2 years ago.
Ok. If that is what is really going on then the fuel pump power wire must be shorted to power. At the fuel pump module connector, the Brown/White wire is the ground for the fuel pump and the Pink/Black wire is the power for the fuel pump. You need to access the fuel pump connector and the wiring from the driver module to the fuel pump and inspect that Pink/Black wire for a short in the harness.
Customer: replied 2 years ago.
So far I do not see any damage in the wiring covers between the module and the fuel pump. It does seem strange that the fuel pump would continue to run with the key out and the module unplugged. Is there a fuse for the fuel pump that can be pulled to see if it will stop? Also, if I put the key in and turn it to the on position the needles on the tach and speedo jump up and down continuously. Could this also be an indication of a short?
Expert:  EricFromCT replied 2 years ago.
That could be an indication of a short or low battery voltage.
There is no fuse for the fuel pump. The wires from the pump, literally go from the pump to the driver module. So if the module is unplugged there should be no power to the pump.
I will send you an offer for the wiring diagram so you can visually see what is going on. You can choose to ACCEPT or DECLINE the diagram.
Customer: replied 2 years ago.
Have checked the pink/black wire as far as I can reach. Obviously I can't get to the connector for the fuel pump without dropping the tank or lifting the bed. The shielding for the pink/black wire was in place and did not appear burned for the entire length. Is it possible that it is something besides the fuel pump that is making the noise I am hearing with the key out? Still stumped by the fact that the engine will not even turn over when trying to jump start.
Expert:  EricFromCT replied 2 years ago.
You have at least 2 issues here. Not sure if related or not yet. If you are hearing the fuel pump run then maybe you should access the connector on top of the tank and unplug it. that way you can be certain. I know of nothing else in the rear to make this noise.
As far as the starting, you will need a test or voltmeter and trace the power circuits from the battery to the starter relay, to the starter.
You probably should determine what is running when the key is out so we have something concrete to try and diagnose.
Customer: replied 2 years ago.
Chalk this one up to the "what the hell" gremlins. Decided to go have the battery tested. Less than 2 year old battery was showing full voltage but no current. After I hooked up the new battery there was no noise coming from the fuel pump area and the truck started right up. Drove it for about 30 minutes and listened carefully after turning off the noises at all. Still quite perplexed, but the problem seems to be fixed.
Expert:  EricFromCT replied 2 years ago.
Ok. So your saying a new battery fixed it?
Customer: replied 2 years ago.
Makes absolutely no sense, but seems to have taken care of the problem.
Expert:  EricFromCT replied 2 years ago.
Ok thats good. Thanks for using Just Answer and please rate my service. Thank you.