The fuel guage is an ohm-meter. It measures the resistance of a coil whose endpoint changes as the float travels up and down. When you disconnect the sender, the resistance is infinite (open circuit) so your guage points strait up. Check the connector to the sender, and give it a clean. If it continues to happen, it's probably the internals of the sender going bad. This is the first car I've seen where the fuel guage works continuously, even when the engine's off. (note to self: check wiring diagram....) Martin #1458 Willie Mack wrote: > This morning when I started my D up to go to class the fuel gauge was pegged > straight up. Luckly when I came back from class around noon and started her > up again, everything was back to normal. Is this something that I should be > concerned with or just come to expect on really cold mornings. > > Thanks > Willie Mack > Vin 5043