Fuel Guage issues
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Fuel Guage issues
My 77 F100 is almost done, but I noticed the fuel guage wasn't working correctly. It moves alittle bit off empty, but that's it. The tank is 2/3 full and I changed out the guage w/ 3 different one's all the same issue. I assume it's something with the sending unit. Looks like I either have to drop the tank or pull the box to get at those parts. Any idea what might be the first thing to check? I replaced the wire harness with out out of a 75 truck, but I doubt that is causing the issue.
Thanks, Shane
Thanks, Shane
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Sending unit float more than likely has a pinhole leak.
Easiest way to tell if the gauge is shot is to go under the truck and ground the sending unit wire, if the gauge pegs FULL, the gauge is good.
Josh
Easiest way to tell if the gauge is shot is to go under the truck and ground the sending unit wire, if the gauge pegs FULL, the gauge is good.
Josh
MSEE
Joined: Apr 2004
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From: Austin, TX
Two possibilities:
1. Pin hole in the float, causing the float to sink and read empty.
2. Lost ground at the sending unit.
Both are very common problems. Try Josh's gauge peg test to see which one it is.
1. Pin hole in the float, causing the float to sink and read empty.
2. Lost ground at the sending unit.
Both are very common problems. Try Josh's gauge peg test to see which one it is.
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From: Slippery Rock, PA
My truck has a 38 gallon tank and I got a universal sending unit for it since the stocker won't work, it was $15 and if you install it correct it works perfect with the stock fuel gauge. That might be an easier option than trying to fix the stock sending unit.
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Josh
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From: Slippery Rock, PA
They must have raised the price, http://www.jcwhitney.com/autoparts/P...oup?Ntt=datcon.
You have to cut a hole in the top of the tank for it to work also.
You have to cut a hole in the top of the tank for it to work also.
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They must have raised the price, http://www.jcwhitney.com/autoparts/P...oup?Ntt=datcon.
You have to cut a hole in the top of the tank for it to work also.
You have to cut a hole in the top of the tank for it to work also.
Not too bad for $22. Kind of a bummer having to create a new hole for it though, but not a deal breaker really.
Josh
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The float is made from two pieces of copper soldered together.
Solder breaks down, gas seeps in, the float slowly settles to the bottom of the tank.
COAZ9202B .. Fuel Sending Unit Float / Available from Ford / Fits: ALL cars/trucks 1957/79.
MSRP: $7.41 // FTE sponsor y2kfordparts.com price: $5.34.
---------------------------------------------------------
COAF9276A .. Fuel Sending Unit Gasket / Available from Ford (not used with in-cab tank).
MSRP: $0.77 // y2kfordparts.com price: $0.60.
----------------------------------------------
C1TF9276A .. In-Cab Fuel Sending Unit Gasket / Available from Ford
MSRP: $5.82 // y2kford parts.com price: $4.19.
----------------------------------------------
On the sending unit's pickup tube is a plastic meshed filter screen that can get clogged up from rust, scale, other debris in the tank.
D1AZ9A011A .. Plastic Meshed Filter Screen-3/8" I.D. / Available from Ford / Not used with in-cab tank.
MSRP: $21.73 // y2kfordparts.com price: $15.65.
Solder breaks down, gas seeps in, the float slowly settles to the bottom of the tank.
COAZ9202B .. Fuel Sending Unit Float / Available from Ford / Fits: ALL cars/trucks 1957/79.
MSRP: $7.41 // FTE sponsor y2kfordparts.com price: $5.34.
---------------------------------------------------------
COAF9276A .. Fuel Sending Unit Gasket / Available from Ford (not used with in-cab tank).
MSRP: $0.77 // y2kfordparts.com price: $0.60.
----------------------------------------------
C1TF9276A .. In-Cab Fuel Sending Unit Gasket / Available from Ford
MSRP: $5.82 // y2kford parts.com price: $4.19.
----------------------------------------------
On the sending unit's pickup tube is a plastic meshed filter screen that can get clogged up from rust, scale, other debris in the tank.
D1AZ9A011A .. Plastic Meshed Filter Screen-3/8" I.D. / Available from Ford / Not used with in-cab tank.
MSRP: $21.73 // y2kfordparts.com price: $15.65.
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Thanks for all the help. Grounded out the sending unit last night and it's not the guage. I just put in 12 gallons of gas to test the guage, so now I'll have to drain it before dropping the tank. Or else just drive it awhile. Got brake issues to solve tonight and then it's on the road again. Everything else is back working.
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