Had customer get towed in today on a no-start 2010 F150 4X4 with the 5.4 liter engine. Come to find out fuse number #27 was burn up, looked like prolonged exposure to heat.
Upon replacing fuse #27 in the engine compartment fuse box (just above the radiator) the truck runs fine now.
Reading up on the issue I gather that Fords has made a fuse relocation kit for this in the instance it melts all the way down and the contacts are missing.
From my years of experience, I would imagine the load of this circuit (fuel pump) is such that the heat and such relative small size of these newer maxi fuses and their contacts, that over time it just melts them away from the heat. Of course the pump could be drawing more amps at it's age of just 220+k miles, and one would have thought a maxi fuse would have been used on such a circuit, however given the fact it is the fuel pump, it's possible they were just being abundantly cautious. I have no doubts that a bigger surface and connector area of a maxi fuse would have prevented this problem. I only say this because this seems to be a well known issue with this particular year and model of F150
Some are saying it could be the module under the tire, some say (myself included) that a wearing pump could be contributing to it, others are saying (myself included) that the gauge of the connection for this type of circuit may be too small to transfer the heat. In any case, I thought of PowerStroker in this instance, figured he must have seen this before and if so - what his thoughts were.
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What is to give light must endure burning -- Viktor Frankl
The aluminum fuel pump driver module located above the spare tire is notorious for rotting out due to road salt and the 2 dissimilar metals. It's worth taking a peek at anyway, but yeah, do the fuse relocation kit too.
I didn't have access to the dealership parts department to get a relocation kit however I did replace the fuse and everything was fine again. I also sent him with the pack of fuses incase it happened again.
In situations like this we charge a standard diagnosis fee that is later applied to any work relating to the same inspection. So if it does come back in on short order I will re-post to this thread with details about the kit for relocating the fuse and or any other problems I found. It would seem the aluminum that is the contacts for the sides of the fuses is really very thin and just folded around the plastic of the fuse. These new fuses wouldn't need much to melt given their new design. You always see brown contacts on fuses and connections that draw power for higher amp motors and such... not so much the solid state stuff, but blower motors, fuel pumps ect. usually have some heat after running for prolonged periods.
You can see where it did actually take out a little bit of the female connector in the fuse box, so it's possible we will have to repair this with the fuse relocation kit. The fuse never really popped, rather the aluminum part that wraps around the plastic fuse melted and pulled away from the contacts.
We will keep an eye on it and report back. If no response that means it's still hanging in there.
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What is to give light must endure burning -- Viktor Frankl
A blocked fuel filter will load the fuel-pump too...
No doubt a failing module from corrosion will cause grief, but is it part of the this fuel pumps electrical circuit ?...
If the fuse is melting away like that from being overloaded, I'd consider replacing the fuel-pump relay also, as it's the main contactor transferring the electrical load...But where does one stop, & how much $$$ does the customer want to spend ?...
Cheers,
Rastus
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"Only an alert & knowledgeable citizenry can compel the proper meshing of the huge industrial & military machinery of defense with our peaceful methods & goals, so that security & liberty may prosper together". Dwight D.Eisenhower.
So I thought I would update this thread to mention that the truck still runs as of this date without any other modification outside of changing the fuse. No doubt that over time the same thing will happen to the new fuse because the design is inadequate for the heat of the draw over time, but that's just Fords for you.
That being said, I had a newer 2013 F-150 roll in with the Coyote style Mustang engine with the same problem... Fuse #27 melted but not blown with the same intermittent crank but no start condition without any check engine light. I knew right where to look and sure enough, same thing. So it is safe to say that Fords is still trying to run a fuel pump off an ultra-mini 20 amp fuse when all they had to do was change it to a bigger maxi and it wouldn't be a problem. Shocked there is not a recall on this issue yet but whatever.
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What is to give light must endure burning -- Viktor Frankl
I'd be shocked that the fuse-box melts before the fuse blows LOL !
Good update SELLC !
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"Only an alert & knowledgeable citizenry can compel the proper meshing of the huge industrial & military machinery of defense with our peaceful methods & goals, so that security & liberty may prosper together". Dwight D.Eisenhower.
It does melt around the fuse area on the box a little, but the contacts are a much stronger material and that is why another fuse will usually rectify the issue. In some cases I guess it would require relocation, and they sell these kits so you can melt the holder next to it! LOL
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What is to give light must endure burning -- Viktor Frankl
