Look by the upper radiator hose and there should be (nearby) a sending unit screwed in to the intake with a wire clipped to it. Check that with a test light to see if it has power, if it does follow it to make sure it gets to the back of the gage. Unsnap (carefully) the dash cover around your gages and unscrew the gage cluster and make sure you have power from the sending unit to the gages. You might go to the library and make a copy of the wiring layout. Also see if that hanging wire is hot with the test light and if it is, or isn't just use the length of it to figure out where it may have come from.
