Bought a replacement fuel sender unit (the cheap-o Taiwan version) through FCP Groton and had my local mechanic replace it on Monday. Since then my tank always reads full (well above full, actually), even after a few hundred miles of driving.

I'm going to try to remedy this myself rather than pay more money to the same mechanic and be without the vehicle for a few days. I understand from the Cleanflametrap.com website how to test the voltage going to the sender (grey lead to ground, look for 10v constant).

What I would like to know is what people consider to be the most likely causes. Is it possible that the float ball arm is somehow stuck in the upright position? Is the problem that Cleanflametrap.com depicts with enamel on the resistor choke very common and would that lead to an above-full reading all the time?

Any and all advice would be much appreciated.