sending units are just variable resistors, they care not about voltage .... a zero to 30 ohm sender is what you should have for an original gauge, so the most likely problem is the gauge itself, unless you have the Runtz wired wrong or a defective one

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