Fuel guage inaccurate and on 24/7

67tiger

Gold forum user
CAT Member
Messages
135
I've posted this issue in the past but actually dug into the wiring today to investigate the problem a little more closely. I know it's something simple I'm missing but I can't see anything out of sorts behind the dash. What got me to dig a little is the fuel gauge now never comes off full, I recently topped it off while sitting over the winter and the gauge came right up as it should, but never came down. So now I have a guage that's on 24/7 and will not come down off of the full mark. I've confirmed the wiring to and from the voltage stabalizer appears correct as does the wiring from the stablizer into the fuel gauge, sending unit is fine. All other gauges respond to the starter switch except this one which doesn't shut off. The car has a completely new wire loom and everything but this functions correctly. If anyone has an idea on how to trouble shoot this please let me know. Cheers, Don
 

artist

Bronze forum user
Messages
43
Fuel gauge

Mine was stuck and could find nothing in the wiring. I got results after pulling the sending unit from the tank and considerable cleaning. Works fine now. Suggest you use the other more complete posts about the gas tank sending unit.
 

Forrest39

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CAT Member
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406
Hi Don,
When you say it's on 24/7, does that imply that the gauge itself may be mechanically stuck? I.E., if you were to remove the gauge from the car it would indicate full?
Cheers, Kevin
 

67tiger

Gold forum user
CAT Member
Messages
135
When I unplug the leads on the back, it returns to 0 gallons, when the ignition switch is in the off position the gauge is still getting power and reads full when I know it's not. So there may be an issue with the sending unit indicated by the false reading on the gauge, but the constant power to this one gauge is what's got me scratching my head more than the incorrect reading on the gauge.
 

michael-king

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CAT Member
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4,132
All the minor gauges are on a daisy chain, so surprised that you are not having issues with other gauges as it sounds like earthing, as you don't get 0 till disconnected, but then I'm thinking all gauges should have problems.... But I would guess earths????
 

Erich

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Messages
148
A short to ground in the wiring leading to the sending unit would give a continuous full reading.
 

67tiger

Gold forum user
CAT Member
Messages
135
Okay, my issue was me being an idiot. After playing with my fuse box to see how the fuel gauge would respond I discovered the brown full time power was feeding the green wires which should be switched power, reversing the power feeds seems to have solved the issue. Now, what to do about a gauge when SWITCHED ON reads full when it isn't. Sending you unit or gauge, I'm guessing sending unit. Cheers!
 
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