Thread: 94 Ford f150 Gas Guage switch

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Hey guys, got in my Ford f150 today and the front fuel tank
switch wont work. The rear tank regristers ok. It was doing
fine when I last drove it a couple months ago.
What are some of the things I should be looking at?
Thanks

In my '90 with factory dual tanks the float sending unit went out on the front tank about a year ago. The pump worked, but no indication on tank level. It's really not hard to drop the tank, and the sending unit is a normally stocked item at the big box parts warehouses.

Originally Posted by rspears

In my '90 with factory dual tanks the float sending unit went out on the front tank about a year ago. The pump worked, but no indication on tank level. It's really not hard to drop the tank, and the sending unit is a normally stocked item at the big box parts warehouses.

Would a sending unit just go bad sitting?

Mine did. The old truck sits more than it moves, and one day when I got in it the fuel gauge fell to "E" when I turned on the key. Hit the toggle to the other tank, and up it went, but fell to "E" when switched back. Started the truck, switched back & forth a few times to confirm that the pumps were both working, and drove it that way for several months, just being sure that I always had some gas in the tank that registered on the gauge. Finally got tired of it, dropped the tank and confirmed the bad sender by lifting the float manually with a good ground on the flange.

Originally Posted by rspears

Mine did. The old truck sits more than it moves, and one day when I got in it the fuel gauge fell to "E" when I turned on the key. Hit the toggle to the other tank, and up it went, but fell to "E" when switched back. Started the truck, switched back & forth a few times to confirm that the pumps were both working, and drove it that way for several months, just being sure that I always had some gas in the tank that registered on the gauge. Finally got tired of it, dropped the tank and confirmed the bad sender by lifting the float manually with a good ground on the flange.

That sounds exactly the way mine is acting. guess I will drive till warmer
weather then fix it. Thanks for info

Could be a faulty switch, but I agree with Roger, bad sending unit

Originally Posted by NTFDAY

Could be a faulty switch, but I agree with Roger, bad sending unit

Could be, but if the pump in that tank is working the chances are it's not the switch since the switch action triggers the pump, sending unit, and return flow controls tank by tank. I didn't trace the circuit out, but I expect the switch hits a relay or two since the pumps draw quite a bit of current.