'72 250 6 with fac temp gauge not hooked up-HELP!

[sof]

I found a 1972 with a 250 6 cyl fleetside longbed (no ac, no power steering, no power brakes and a 3 on the tree transmission) with 55K original miles on it.
First, I have been so excited every time I look at it I almost can't stand it. It was in an older fellas garage on blocks without the wheels on it since his wife died. A young guy bought it and he and his brother replaced to brake master cylinder and the two back brake cylinders and the wires, cap and points in the distributer. He wanted a long bed so I bought it from him and drove it home. I replaced the gas tank since I knew it was rusted and have done a few other minor things. One thing that is puzzling me is it has a factory temperature gauge that has no wiring to it. The sensor has a wire running to it so I don't know if it just has a dash warning light that works or not. I really would like to hook up the temperature gauge on the dash and would like to know how. If you guys lend a hand I sure would appreciate it!
Thanks!
Grinnin' Guy in Lubbock, Texas