Fuel Guage not working
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Freshman User
Joined: May 2006
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From: North Carolina
Fuel Guage not working
1986 F-150 w/302 Fuel Injected and dual tanks. Fual guage was working part of the time for the last 6 months, but now it does not work at all. My solution so far has been to put gas in both tanks and when one runs out switch to the other and get to a gas station. I'm ready to try to get this thing fixed,but need some advice on where to start. Also, no matter what climate control selection that I make, the air blows out at the panel vents. Wonder if this could be a vacuum line. Thanks
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Joined: Jan 2001
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From: Virginia
Go to one of the gas tanks and unplug the wiring. Switch the tank selector switch to the one you are working on, turn the key to run(but don't start the engine) and then find the sending unit wire at the tank and ground it. I am thinking it's a yellow/blue or blue/yellow, but I am not totally positive.
When you ground the sending unit wire, the fuel gauge in the dash should swing full scale, empty or full. Then take the sending unit wire off ground and let it hang in the air. The dash gauge should swing full scale the opposite direction. If it passes this test, it means the guage, the tank switch and the wiring to the tank are good, and there is something wrong with the sending unit.
You can do this same test with the other tank so long as you switch the tank selector to the proper tank.
When you ground the sending unit wire, the fuel gauge in the dash should swing full scale, empty or full. Then take the sending unit wire off ground and let it hang in the air. The dash gauge should swing full scale the opposite direction. If it passes this test, it means the guage, the tank switch and the wiring to the tank are good, and there is something wrong with the sending unit.
You can do this same test with the other tank so long as you switch the tank selector to the proper tank.
New User
Joined: Jan 2008
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same system of these applies to yours
https://www.ford-trucks.com/forums/1...uel-gauge.html
https://www.ford-trucks.com/forums/1...-1-2-mark.html
https://www.ford-trucks.com/forums/1...f-the-peg.html
https://www.ford-trucks.com/forums/1...uel-gauge.html
https://www.ford-trucks.com/forums/1...-1-2-mark.html
https://www.ford-trucks.com/forums/1...f-the-peg.html
Senior User
Joined: Jun 2007
Posts: 135
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Not sure if this is the issue, however mine did the same thing. Sometimes it would work, get down to under 1/2 tank it wouldn't....turned out to be the float. I had over time got some gas in it. I took out the sending unit, took the float off the clip and shook all the gas out of it, mine is the cylinder type and you can't buy just the float, you have to buy the whole unit. I took some JB weld and covered the small crack. Been working now for about 4 months.
