Fuel sender basic testing?
 

Can one short the fuel sender wiring to ground and have the gas gauge read full? The is the way I would normally go about initial testing for a bad sending unit on my other old cars.

I don't have a manual for this car yet, but I assume the tank is under the compartment for the soft top and the fuel gauge sender can be reached and removed from in there once the hard top is off and the soft top is out of the way?

You are correct about access. There is at least one post on how to remove the sender.

The gauge is a potentiometer, and the sender supplies it with resistance to ground according to the level of its float. There is a second circuit that supplies ground at about 1/8 of a tank to turn the warning light on.

Sometimes the float gets stuck and you can free it up by soaking it in carb cleaner. Other times the whole thing goes TU.

Great stuff. Thanks.