Help, need a parts source

Sean I have auto meter connected straight to the ford tank sensor. I might be all wet on this one but there is sometimes a module that sends a constant signal to the gauge. When you drive the sensor in the tank is constantly moving because it's like a toilet bowl valve. thats why it works better when close to full. I did my own wiring so I would ask some one that knows the mustang system first before spending money because the Ford dealler will not take back any thing they order, Those crooks. You might want to try mustangs unlimeted the have a web site, I'll look for my catolog and check. they sell things like that. It's around here somewhere