Non functioning Gas Gauge

[T. Highway]

I just purchased this truck 3 weeks ago and I'm in the process of learning what makes it tick. This truck is a blast to drive.
The truck has had a new fuel tank put in by the previous owner.
I need to know what I should look for first. All of the other gauges work and the rest of the electrical system components function properly. Is there a way to check the sender and gauge instead of just throwing in new parts?

Thanks

 

[sklemm]

I can't say I am an expert on your model, but it is of a similar vintage to my M52 and I just went through swapping out the gas tanks on it...

I had a similar issue with no working fuel gauge.

This is what we did to troubleshoot the issue:
If you put a resistance meter on the fuel sender located in the tank the resistance should change as you move the level up and down (No resistance when full and lots of resistance when empty/or the reverse of that, I can't remember).
That some test should be repeated at the connections behind the dash.

If you get changing resistance then my money is on the gauge.

 

[jimmcld]

Look for a bad ground. All that sending unit does is provide a ground connection for the guage. You do know that there is an access panel in the bed?

 

[T. Highway]

Scott, Thanks for your input. I got a trouble shooting guide from someone on the g741 site that spells out exactly what you mentioned. I will test the sender and wiring in a couple of days.

jimmcld, I thought it was the ground to, but it wasn't.