Stumped on my gas gauge not working - '87

[Tippy]

My gas gauge started acting erratic years ago, and then stopped. Tapping the "glass" would usually get it working again. But then, it totally stopped.

Took some time tonight to work on it.

This is what I did:

1. Sanded spade contacts on back of gauge.
2. Slightly squeezed female connectors more closed.
3. Pulled gauge and oil level gauges out of chassis (nothing out of ordinary I could tell)
4. Applied 9V's from a 9V battery and the gauges pegs full.
5. Put DVM on hot and ground connectors from car and am seeing like 8.9X volts.
6. Merge the connectors back on, still indicating empty.
7. Disconnected all connectors except the 2 and no change.
8. Slid connectors on and off many times plus wiggling to no avail.
9. Hooked the 2 main wires for gas gauge and brown ground only to no avail. Thinking maybe the 2 gauges were possibly interfering.

I admit, I'm TOTALLY baffled.

How can I get the gauge to work with a 9V battery and see 9V's with key on but when properly hooked up, still showing empty??

[Tippy]

Duh, gauge doesn't work off voltage, rather resistance. Will be testing ohms at the sending unit.

[Matt Monson]

My 914 fuel gauge has never been accurate. The problem on my car us the float in the tank. It is stuck and cannot rise all the way to the top. I can fill it all the way and it never reads more than 2/3.
Are you sure the problem isn't in the tank with float getting stuck and hung up? Mine is totally accurate at the bottom but it will never show full.

[Tippy]

Matt, just yanked the sender and it was the problem. The tube that shrouds around the sender fell off and the 2 wires were broken from the solder joints. Resoldered but it failed in the way back in.

$180 is a lot of money for this paper mâché made part. Bluah.

May try to resolder again.