Gas gauge not working

Hi and thanks for using 2CarPros.

That can be caused by a few things. First, a bad ground to the sending unit or the rheostat itself is bad on the float level gauge.

First, start by checking grounds. I have attached two pictures. The first is for the ground at the sending unit (fuel tank) and the second is under the instrument cluster. You will need to check continuity on the wires. To do so, you will need a multi meter. Here is a link that shows how to use one:

https://www.2carpros.com/articles/how-to-use-a-voltmeter

First, identify the wire in question and follow it to where it attached to the body of the vehicle. Between that point and the component in question, check continuity while moving the wiring around to see if there is a change.

Do this and let me know what you find. Unfortunately, I don't have a schematic of the grounding points on the truck most likely due to year. Also, I don't know where you are located, but if you are in the snow belt or an area where roads are treated leading to rust problems, the underside of these vehicles are rust prone and grounding issues are common.

Take care,
Joe

They used a brass hollow float on these that would get a pin hole and fill up with gas, but usually would stick to the bottom. Also the sending unit card in the tank would get gummed up. Try some fuel additive and drive around, otherwise the fuel pump will have to come out.