It's more likely the float sensor in the tank and you would have to change the fuel pump because its all one piece the part is about $400
how do you fix a gas guage on a 1989 ford aerostar
Then fix it
Have you checked the gas floater in the gas tank?
The fuel sensor is in the gas tank and probably needs replaced, the tank will have to come out to fix it.
Could be bad gauge or float stuck in fuel tank
Its probably the float in the gas tank that tells how much fuel is left in the tank... its sticking.
Most fuel gauge problems are the result of a faulty fuel gauge sending unit located in the fuel tank.
sending unit
check the wiering /our your sending unit no good
check sending unit in tank and check gauge for proper operation and connections, and grounds
You will have to replace the fuel sending unit inside of the fuel tank.
i dont speak car!