Aftermarket tank & Sending Unit not working correctly with OEM Gauge

[buckskins4ever]

I need help folks. I purchased the Aftermarket Frame tank from LMC Truck and it came with a Sending Unit......I just got it installed yesterday and all seems to work great for except one thing.......................I have at most 8 gallons of fuel in the tank, and the gauge shot past the FULL mark and kept going for another 2 inches. If you can imagine the gauge as a clock face, the fuel needle is pointed at about 4pm when it should have stopped about the 12 since it was only about half full.

Has anyone installed this tank and come across this issue as well??

[71K20chevy]

Tank should be grounded...if it is, you have a loose connection somewhere

[buckskins4ever]

grounded the ground wire of the sending unit to the frame directly, and the tank is actually bolted directly to the frame rails. i assume the sender wire was correctly connected since its reading something. but not sure why it flew past the full mark with so little fuel.

[71K20chevy]

So your sending unit has two wires? One for ground, one that goes to the fuse panel?

[71K20chevy]

The single wire coming off the sending unit shouldn't go anywhere except to the fuse panel. All of our truck gauges read over full when the wire is not connected.

[ole dollor]

if its was working fine with your seat tank, then you have the wrong sending unit, or bad ground i would think, i think ours are like 90 oms . might double check that.