I'd disconnect from the sender and check the wire with a meter to see if it's developed a short to ground between the gauge and sender - if it's OK, then it should be the sender, pull it and check it, the variable resistor on it may be rotten

Bill


Moved over to the Passing Lane

"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir
"When we tug a single thing on an old truck, we find it falls off" ~ me
Some TF series details & TF heater pics