fuel gauge not working

[charger_mike75]

I'm new here, hope someone can help me with my problem. I'm working on my 68 charger and i put a new gas tank and sending unit in and now my fuel gauge will not give an accurate reading, won't go over 1/2 when tank is full.
i've taken the sending unit out of the tank and operated it manually and the gauge will work like its supposed to. I think it's a ground issue but it still leaves me scratching my head. i've even attached a ground wire to it but that didn't seem to help. any thoughts or ideas would be a big help

[Rolling_Thunder]

is the ground strap in place that connects the fuel line to the sending unit ?

[Plumcrazy]

is the ground strap in place that connects the fuel line to the sending unit ?

Which also means the fuel line itself must be properly grounded to the body
You could also try running a wire between the sending unit and negative battery terminal just to verify it is a ground problem.

[charger Downunder]

You may have to bend the float arm down slightly.

[charger_mike75]

I put a ground strap on it and it didn't make any difference. does the gas tank need to be grounded, or just the sending unit?

[Plumcrazy]

I put a ground strap on it and it didn't make any difference. does the gas tank need to be grounded, or just the sending unit?

Just the sending unit needs to be grounded.   Did you try running a wire between the sending unit and negative battery terminal ?

[charger_mike75]

no just to the body i'll give that a try

[smokinrt]

I'm new here, hope someone can help me with my problem. I'm working on my 68 charger and i put a new gas tank and sending unit in and now my fuel gauge will not give an accurate reading, won't go over 1/2 when tank is full.
i've taken the sending unit out of the tank and operated it manually and the gauge will work like its supposed to. I think it's a ground issue but it still leaves me scratching my head. i've even attached a ground wire to it but that didn't seem to help. any thoughts or ideas would be a big help

My service manual shows the ground clamp snapped to the fuel line and snapped onto the fuel vapor line coming out of the tank, thats it, nothing (ground) goes into the tank.  Unlike GM type grounding systems are quite different.

[histoy]

I agree with Charger Down Under.   I have installed 3 new sending units, and all were grounded properly, but wouldn't read full.   Had to bend the float arm on all 3 to get them to read correctly.   My friend has a Super Bee and had the same problem.   He drained all the gas from the tank, then put in 10 gallons of gas, and adjusted the arm on the sending unit to read 1/2 full.  It's read correctly after that.

[charger_mike75]

so if i bend the arm down until it reads half, wouldn't that mean that the gauge would't go under half???
I will give these helpful suggetions a try but if they don't work I am real tempted to trash the gas tank and go with a fuel cell. 

[darrin75]

I have the same problem here, what's up with the new repro sending units?? I hope the bend down thingy works for me..

[roger01]

worked for me ....had to take the sending unit out 3 times though