Nervsofsteel

Hi all. First post but I hope it's of value to someone. I have a 2013 F150 FX4 3.5l. It ran out of fuel three times in the last 2 months and all three times the gauge read in access of a 1/4 of a tank and a hundred miles remaining. I fix the problem today and I wanted to share what I found at a couple of pics.
My my truck has a 36 gallon tank and when it ran out Friday only put just enough fuel in it to ensure that I got home. I dropped the tank on it today and found the sending unit on the fuel pump assembly to be burned out. Slightly concerning for something that is in the fuel tank, but you can see where it has overheated. The sending unit was available from Ford for the same price as he local auto parts stores, however with it having run out of fuel 3 times I went ahead and change the entire assembly.
Thought this might be beneficial for anyone experiencing running out of fuel when the truck is still showing more than adequate fuel.

gDMJoe

This is the result of consistently, and routinely, running the vehicle and having ¼ tank of less of fuel in the tank.
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• the fuel pump is cooled by the fuel that surrounds it.
• low levels of fuel cause overheating and strain on the fuel pump.
• low levels of fuel causes moisture, condensation (water) in the tank, contaminating the fuel.

Keep fuel tank at least ½ full for everyday driving. On long, extended hauls don't allow the fuel tank to go too low (e.g. less than 1/8th of a tank). AND, when filling-up, stop after the 1st click-off of the nozzle.
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SALEEN961

iTrader: (1)

I'd be inclined to agree with you, but the fuel pump didn't fail. For the sending unit to be overheating so badly that it's melting back the insulation on the wires and burning the PCB by the solder joints in the middle of winter in the Midwest something is wrong. I've replaced plenty of fuel pumps and even when a pump has failed signs of overheating like the OP has shown us in his pictures aren't normal.

RLXXI

Certainly is odd to see that burned, all there is on that circuit is a variable resistance.
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Nervsofsteel

Thanks Joe, I was putting information out there for anyone who has had the problem of running out of fuel with the fuel level and computer still showing adequate miles to empty. After 130k miles of driving this truck and 30yrs of owning F150s I was definitely not looking for a critique of my fueling habits.

After 130k miles this is the first major thing I've had to do, and compared to splitting any of the cases or getting into the motor, I would not consider this major.

​​​​​ As additional information, the tank was lightweight and easy to manage with a floor jack and a 2-foot section of 1 by 12 to distribute the weight. Dropping the driver side step gained me enough clearance that I did not have to lift the truck at all. The swap took me about three hours but I hand cranked everything since I did not have access to my impacts and air tools.

Midnightcity

Thanks for the info on dropping the tank. May be doing this soon to inspect my sending unit. Different problem but good to know it's not too bad a job.