I recently installed a new fuel pump in my 1995 E-150 5.0 L full size van. The fuel gauge worked just fine before dropping the tank and unattaching the old fuel pump. I carefully reattached the sending unit to the new fuel pump and after reinstalling the gas tank the fuel guage always reads full. VERY FULL. When I turn the key on it seems to want to find it's real fuel level position then it quickly goes to the far right well past the normal full position. Is this a ground problem? Any thoughts???

Thank you,

Peter in San Diego

 

In a nutshell, there are at least two different pumps for the 95 E150's. There is the one pump for the van with the 35 gallon tank, which we own, and then there is the pump for the van with dual tanks (20 gallon each I believe). From what I know, the pumps are essentially the same, but the sending units are different, for obvious reasons. My initial guess is that you bought the wrong replacement pump.

We own a 95 E150 with the 35 gallon tank and the pump failed about two years ago. Our shop put in a new one and we had a similiar problem to yours, althoug my memory seems to remember it reading too low even when full (but my memory may be off here). Anyway, I talked with a Ford dealer and a few other folks and discovered the difference in sending units. I quizzed my shop, and they initially said it wasn't the case, but after I forced them to double check, the fessed up and put the correct pump and sending unit in it. No problems since then.

Actually, what you are describing would make sense it they put a 20 gallon pump in for a 35. The sending unit thinks it is full when your tank has 20 gallons in it, and when you fill it all the way up to 35, it must go nuts and try to go as far as possible.

Let us know what you find out. A Ford Dealer parts shop should be able to tell you if you have the right part number or not. Maybe you can just swap sending units, but I doubt it.

Jim1995E150

 

HI Jim,

Thank you for your reply. We only exchanged the pump. They looked identical when I looked at them side by side. The sending unit was not replaced but only taken off the old pump and put onto the new pump. We replaced approximately 12 gal of gas that we removed from the tank and as mentioned when the ignition key is turned to on the fuel gauge starts to find its position and then immediatley goes to well beyond the full reading. The symptoms duplicated when the fuel tank was filled with about 19 additional gallons confirming that it is a 35 gal tank. I wonder if a wire got pinched and it is grounding out somewhere. Any further ideas would be welcomed.

Thank you, Peter in San Diego

 

Peter,

It could be a short of some sort of short, but I would still run by your procedure with someone from Ford just to double check there isn't something internal to the pump that is different for the 35 gallon pump vs 20 gallon pump. I'm grasping at straws here, but possibly all the "brains" are not necessarily in the sending unit and could be shared/controlled by the pump itself.

Good luck. Jim

 

The following is true for a 1993 van:
If your needle is going all the way to the right, then you have no connection between the sender and the gauge. The sender reads full with a resistance of 145 Ohm and empty with 23 Ohm.
So if the resistance is more then 145 Ohm, the needle goes to over-full. Hence, if the wire is not properly connected or broken somewhere, the the resistance is very high (Mega-Ohms, litteraly) the the needle does what you experience.
Sorry, but this sounds as if you will have to drop the tank again.

Alternatively, in the wiring harness to the tank (pump and sender) there is a yellow/white wire, (it just looks yellow!)which is the sender wire; short this out to ground and see what the needle does now; bet it will show empy,or less, as the resistance is now less than 23 Ohm.
If this is the case, you know for sure the wiring to the dash is OK, and the sender wire loose, or of course, the sender ground is loose/broken.The fuelpump and the sender use a common black wire to ground, but it still could be broken between the sender and the splice.
Cor