86 C10 4.3 Gas Gauge Incorrect

[tablerock4]

Recently replaced my gas tank. Ever since, my gas guage will not go down past the half tank reading. It works fine when the tank is full and down untill half tank and then it just hovers. Any ideas?

Thanks

[C-10volvo]

take the dash apart, and unscrew the gas gauge out and clean the termanals on both sides with a wire brush. if that doesnt work, then you might have to drop the tank and do the same to the connections on the sending unit.

[tablerock4]

Thanks for the tip! Looks like I'm gonna have to get into that fuel tank. A freind was telling me that he has seen the float assembly get bound or stuck some how during reinstall. I really would like to check this out with the tank in place. I heard the bed can be removed or slid back. Has anyone ever done this on a 86 or similar year C10 Fleetside? It looks like there are about 8 bolts holding it on but that just seems too easy...


Any tips are appreciated

Thanks

[NeCrOmAnCeR]

Sometimes the sending unit does get stuck, or is bent incorectly for the tank. Ground the sending wire to see if the guage goes to zero.

[Blue Beard]

Some times it's just in the wiring when reconnected..

[tablerock4]

OK, I have a question. It looks like there are two wires at the top of the gas tank where the fuel lines enter and the sender/float assy goes in. One wire has a rubber boot covering its connecter and is located toward the center of this area. The other one does not have a rubber boot and is attached near the edge of this area. Which one is the wire I should touch to ground? I'm doubtful I will be able to do this because the rubber boot will make it difficult if that's the sending wire.

Next, there is very little room to manipulate these wires with the tank and bed in place. However, I did use a long needle nose to remove the booted wire. When I did this, the guage went all the way past full. If you can visualize this, the guage hand went to a position as if it was the minute hand on a clock reading 20 minutes after. Do you think this is normal or relevent? It almost seems as if the range of the guage has been turned 1/3-1/2 to the right (ie. a 1/2 tank reading means empty etc.)

Thanks

[87 STEPPER]

That is a normal condition for the needle to go past full when the ground is lost so that tells me that both your pwr & grn are ok.

So id'e go tank diving and look at the float assy to see if any of the float is missing or damaged also chk the float hard wire and see if it is bent in a way that would appear to give an inaccurate guage reading.

If all looks to be ok then it 's the senging unit rehostat assy. at fault and would need to be replaced.

[magnethead]

as far as removing the bed: undo any electrical connections going to lights, unbolt about 6-8 bolts in the bed floor, and using about 6 or 8 people, lift the bed and have another person drive the truck out slowly from underneath the bed.

[tablerock4]

Thanks guys. I was afraid of that. I'm not looking forward to the job, it was a real pain trying to attach those hard fuel lines once the tank was in place. It'll be worth it though to have that guage working.

Cheers

[magnethead]

Pull the bed off and it'll be alot easier to work with.