ICQ>

Nick ---

It's possible the wire from the sending unit has become shorted to ground. That would simulate a full-tank condition. Before removing your sending unit, disconnect the wire at the sender and see if the gauge still reads full. If it does, the problem is with the wiring somewhere in the harness. If the gauge drops to empty but then jumps to full when you reconnect the sender, the sender is defective, the wire is grounded in or at the sender, or the float might be jammed in the "full up" position. Be sure the ground wire going from the car body to the sender is sound and connected at both ends.

The sending unit is a very simple mechanism and can probably be repaired easily rather than purchasing a new one.

I had a similar problem with an '82 240 that sat for a year with 1/2 a tank -- the float mechanism developed a bit of rust, and the gauge would not register less than 1/2. I had to remove the sending unit and clean up the rust -- it's been fine since.