2001 gtx rfi fuel sending unit

[kenf]

I have a 2001 gtx rfi and the fuel guage is not reading and the alarm comes in with a full tank. I removed the unit from the fuel tank to check it out and every thing looks good I cleaned the contacts on the float cicuit board and the float ohms fine, I put it back in and not I have no bar graph. What could have happened and where can I find the whole unit for sale cheap?