Gas gauge on my 1997 F-150 is stuck on full. I haven't checked the float yet, but I was wondering if maybe the ground is bad? What will the gas gauge read if the ground is bad, and where would I find the ground point?

 

Hi Roger,
There are a few ways to go about this, A lot depends on what test equip you have, and access to the top of the fuel tank..
To me it would be easier to open the dash lay it back so you can get behind the printed circuit then remove what you have to in order to isolate the gauge from the connections. Then with the key on and only the power to the gauge connected, and the signal wire off the gauge. The gauge should go back to empty.If that is OK then I would start looking for the signal wire that comes from the tank gauge unit to be grounded someplace. It could at the plug near the tank or anyplace between the plug and the gauge inside the vehicle. t sounds like a lot of trouble , but only takes a few minutes to check this out. If you can get to the plug at the tank and unplug it .If the gauge goes back toward empty that wire may not be involved.

 

Thanks Hank!!!