Did grounding that wire turn on the light? If it did, then something is up with the wiring or the bulb.

I am not sure how the sending unit is setup electrically. You could pull the unit and see if the circuit closes on those two pins when the float is all the way down.

 

just tested the light again and it turned on when i grounded the wire, perfectly like it should. I was doing it wrong before.

this pretty much verifies that the problem isn't in the electrical circuit or the bulb, sounds like its in the fuel sending unit. I'll likely pull the sending unit one of these days and see if I can do anything to fix it.

 

Did the light turn on when you jumped from the lt green/red wire to the blk wire, or did the light only come on when you grounded that wire to a good ground?

 

i took off the hatch you mentioned, and i believe my car is wired differently. I took the hatch you were talking about off and there was no three-prong plug below it. there is, however, a three-prong plug above the hatch in the trunk compartment whose wires lead through the hatch. This is where I tapped into the green/red wire.

The plug does not have an all black wire. A black wire passes through the grommet in the hatch, but is not a part of the plug, and there was no way to short the green/red wire to it without stripping or tapping it.

The plug does, however, have a black/silver wire passing through it. shorting this to the green/red did nothing.

shorting the green/red wire to a good ground however DID turn on the light.

 

This is the picture that I am giving the information from. This is from a 96 shop manual.