Gas gage!

[nheller76]

Ok so my gas gage went out yesterday and I've done some random things to fix it and nothing. So I first replaced the cluster fuse, nothing. Then the actual gage still nothing. Anyone got ideas? It's a 78 buy the way and it has dual tanks. It was also working before.
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[pontgta]

sending unit , but check your grounds....

[nheller76]

Do u know what grounds to check?
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[dieseldawg142]

a wire from the sending unit on top the tank to the frame. seems unlikely both tank grounds would crap out at the same time though. the selector switch also grounds out on the frame threw a bolt. the gauges share a common ground.
you say your gauge went out- whats the needle doing?

[nheller76]

Pointing all the way down to south. It will stay there when turned off too. The new gage doesn't move at all. Could I have popped a fuse I don't know about. It was working for both tanks before even though my selector valve has been temporarily bypassed.
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[nheller76]

Could it be the printed circuit on the back? Can u get those from like a napa or something?
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[frog210]

I had a brown wire cut when I got my truck, its a 74 w/ dual tanks, it was a brown wire that ran from the pass frame, to the firewall , might want to get under your truck and chech all your connections and wires
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[pontgta]

Did you have voltage when you replaced the gauge? you should have had 12v at one of the terminals and the other terminal is driven by the sending unit(which is a ground). This would determine if its a ground or power issue. My sending unit is switched though the selector valve but yours might be different(i have the 6 port) If you have a 3 port valve, the gauge should be controlled by the switch.

[Recian]

That's the first thing I'd check. Knowing your signals at the gauge will tell you where in the circuit the fault is. if there's no power in or no ground side. If both are good then it's the gauge. I've got a lot of them laying around along with circuit boards.

[motornut]

the ground is seperate for the gas if you have a stock tach
sender wire off goes over full
shorted to ground goes E

[nheller76]

I have the big gas gage, so I checked I don't have power to it. I'm thinking of buying a little gas gage to replace it and just buy pass my regular gage. Can I do that? I also fallowed all my wires from my switch to my fire wall plug, then my plug to above my tank (lost it after that) and not a problem. So I'm guessing its my printed circuit?
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[motornut]

do you have power elsewhere in the cluster?

[nheller76]

Yea I have power to the dash lights and the blinkers. I'm really confused as to what is going on with it. The gage will move when u plug in the cluster plug. It will go to a quarter tank then stop. What amp fuse do I need to put into the fuse box maybe I put the wrong one in? Other then that I'm going with a secondary gage if u know what wires I need to use that would be helpful. Thank u motornut for all your help!
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[motornut]

Originally Posted by nheller76

Yea I have power to the dash lights and the blinkers. I'm really confused as to what is going on with it. The gage will move when u plug in the cluster plug. It will go to a quarter tank then stop. What amp fuse do I need to put into the fuse box maybe I put the wrong one in? Other then that I'm going with a secondary gage if u know what wires I need to use that would be helpful. Thank u motornut for all your help!
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no I was wondering about other gauges etc
but if the others work could prob say the ground is good then
I'd wana check for power at the pink wire in the pic
bout a foot from the plug
I think it's a smaller 10 amp fuse
no probs, hope it helps
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[nheller76]

Well all of my other gages, except the amp, didn't work so I just got some others and put them in. Ill take a pic and show ya later. But before I did that is when I lost the gas gage. Ill see if I can get something from the pink wire and let u know.
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[motornut]

when testing the pink, test using the ground wire, and the body
then use another power ,and check the ground again

[nheller76]

Ok I'm a duff! Changed out my fuse (I Hess the new one I put in was bad???? WTF) and BAM she starts working. Every corner I take or every time I stop and start it goes back down to zero but now I know how much I have in the tank when it is running. Thanks guys for all your help.
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[motornut]

Originally Posted by nheller76

Ok I'm a duff! Changed out my fuse (I Hess the new one I put in was bad???? WTF) and BAM she starts working. Every corner I take or every time I stop and start it goes back down to zero but now I know how much I have in the tank when it is running. Thanks guys for all your help.
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I've had them look fine but old I guess tarnished?heat up enough to move away like the old Christmas flashers lol
if your still in there would you
run it separate /alone to Grd
some thoughts are the sender /lack of baffles causes the bounce
i doubt that , people would be returning them
with different ideas for the " fix"
I found when I added a ground , (the idiot cluster didn't have one)
and I did change the gauge too, it moved and went smaller
so the ground isn't used with other parts
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