Could it be a disconnected wire? If so where is it located?

 

Low-fuel sensor is part of the fuel sender assembly on the gas tank, just behind the plastic panel to the rear of the drivers rear wheel well. 3-wire connection; 2 for the gauge, and one for the low-fuel "dipping sensor."

If the wire is open anywhere between the sender and instrument panel, the light will come on.

 

Hmmm that's funny, mines never came on lol even when I ran out of gas a few times.

 

I believe it's only on the 84 and 85 models. It's the fuel sensor in the front of this picture versus the one in the back that only measures the amount of fuel.

 

Yep, got an 84 gslse and an 85gs neither one work lol. Maybe one day it will.

 

I'd pull the sender out and clean up the whole system if it was mine, just to be safe.

 

Bad bulb?