Thanks for your service to our country.
The sender you linked is just a sender, no pickup tube for the fuel. That may make the gauge work, but will sure make problems for engine performance...
IronMaiden has good advice in finding out the range of resistance of your current sender.
If your sender is a factory type, the resistance range 73 ohms=full tank to 10 ohms=empty tank. Depending upon how much fuel is in the tank when you measure resistance, your reading will be within this range. if it isn't, there is another problem. Zero(0) resistance means a short in the wiring to the gauge, or the gauge itself. Infinite resistance (no reading at all) indicates either a broken wire or a bad sending unit, or bad ground for the sender.
It is entirely possible to have a combination of the above mentioned problems. (ie, shorted wire/bad sender)
You may have to drop the tank, replace the sender renew the ground, and rewire to gauge before you are done.
The easiest thing to do first is check resistance by disconnecting the sender wire at the gauge, get a multimeter, set to resistance range, find a good ground for one of the leads, and hook the other lead to the sender wire.
See what ya got, then proceed from there. God bless.
Jon In Tucson
Jeremiah 17:7 "But blessed is the man who trusts in the Lord, whose confidence in Him."
"The secret to a Jeep, especially a CJ, is you can't
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