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gas guage broken please help
- Thread starter roy87
- Start date
If you do a search there's some very good threads on this. DYeager wrote up a very informative thread some time back.
Confedneck79K30
3/4 ton status
just drive it til it runs dry then fil'er up...
probably a loose or corroded ground from your tank over to your frame, black wire.. You can check the gauge by grounding out the sender wire, which iirc is a tan wire with white stripe, fuel pump will be pink... when the sender wire is grounded, the gauge should pin to full, if not there's a prob with the gauge... If it pins, the prob lies in the sender connections, ground or sender itself...
Actually it sounds more like a connection, ground or sender. Or the gauge... Float sender would be most unlikely of all for a bouncing around condition..
Confedneck79K30
3/4 ton status
usually when a float goes bad it's because its soaked up and full of fuel and doesnt register properly, a bouncing gauge can be a bad sender though, i had an s-blazer with a bad sender, there was 2 tabs that rode along a resistance bar kinda thing and one broke off causing the sender to make the gauge bouncy... (re read my post here and sing "im bossy") LOL
Bouncy gauge is not caused by the sender. The reading "damping" (why it doesn't fluctuate quickly as you accelerate, corner, up or downhill, hit bumps, etc) is handled in the gauge itself. The float always moves, very easily, and the only reason you don't see that movement constantly is that the reaction/interpretation of the float/rheostat in the tank is slowed down by the gauge. This is also why the GM manual states that you need to give the gauge time to respond when testing the fuel gauge circuit operation. There are no electrical components (carbed gas engine) on the sender other than the rheostat that is actuated by the float.
Even grounding or breaking the ground of the gauge sender wire does not peg a fuel gauge instantly, given that everything is working correctly in the first place.
Now of course, as soon as you make an authoritative statement like that, for some reason or another it will turn out to not be true.
However, there are likely other issues as well, the fuel tank gauge circuit is a common "failure point" in these trucks.
But, even if you pull the sender, you can likely clean it up. Never hurts to touch up the sender ground either.
Even grounding or breaking the ground of the gauge sender wire does not peg a fuel gauge instantly, given that everything is working correctly in the first place.
Now of course, as soon as you make an authoritative statement like that, for some reason or another it will turn out to not be true.
However, there are likely other issues as well, the fuel tank gauge circuit is a common "failure point" in these trucks.But, even if you pull the sender, you can likely clean it up. Never hurts to touch up the sender ground either.
Confedneck79K30
3/4 ton status
dyeager535 said:Bouncy gauge is not caused by the sender. The reading "damping" (why it doesn't fluctuate quickly as you accelerate, corner, up or downhill, hit bumps, etc) is handled in the gauge itself. The float always moves, very easily, and the only reason you don't see that movement constantly is that the reaction/interpretation of the float/rheostat in the tank is slowed down by the gauge. This is also why the GM manual states that you need to give the gauge time to respond when testing the fuel gauge circuit operation. There are no electrical components (carbed gas engine) on the sender other than the rheostat that is actuated by the float.
Even grounding or breaking the ground of the gauge sender wire does not peg a fuel gauge instantly, given that everything is working correctly in the first place.
Now of course, as soon as you make an authoritative statement like that, for some reason or another it will turn out to not be true.
But, even if you pull the sender, you can likely clean it up. Never hurts to touch up the sender ground either.
mucho agreed on the cleaning things up statement.. never hurts to have good, clean, new grounds..
awesome guys thanks for the help i'm not very sound when it comes to mechanics and all this stuff so i'm looking for the ground thats gona be on the tank its self? and i need to make sure that it is geting grounded and also clean it off right.
yeah, it runs from the frame over to ring that retains the float sending unit and pump down in the tank.... Unfortunately the tank needs to be dropped to check your 2 connections on the tank, sender and ground... You can check the ground to frame without dropping the tank... If by chance you have a 3" bodylift, sometimes you can inspect those connections on top of the tank without dropping it...
When I check the gauge by grounding the send wire, I'll usually just cut it in front of the tank, ground it to frame.. then you can splice it back together..
When I check the gauge by grounding the send wire, I'll usually just cut it in front of the tank, ground it to frame.. then you can splice it back together..
Don't you have a connector on the send wire?
Even my carbed setup had a single prong connector, you could just disconnect it and stuff a piece of stripped wire in there to touch to ground.
Even my carbed setup had a single prong connector, you could just disconnect it and stuff a piece of stripped wire in there to touch to ground.
Mine had been replaced with a butt connector at some point.. 
Makes sense that one was there....
So I just snipped it close, removed thiers and put my own in...
Makes sense that one was there.... So I just snipped it close, removed thiers and put my own in...
