Note- with all gauges and senders that use screw-on electrical connections, you need TWO wrenches. One grabs the big nut bearing against the case and the other grabs the small one to tighten the wire against the big nut. Using only the small nut to tighten securely, you run the very real risk of pulling the guts of the gauge or sender apart, to make an 'open circuit'. It may not leak (gauges especially!) but it also may not work even if new.
Second caution- use ONLY TWO LAYERS of teflon pipe tape on all liquid senders. I've seen 6 or 7 layers used on some senders "to be sure it don't leak". Teflon tape is an insulator and if you use too many layers, the sender, which depends on grounding against the block to work, may not ground it's case. And again, you'll get an open circuit. Check all inop' senders with a grounded wire to its case before throwing away a perfectly good sender. Temp senders seem especially sensitive. My 2 cents-