1978 Campmobile
I wanted to try and restore a dead fuel sender. I'd never put it back in a tank again: cadmium plating has come off with oxalic acid.

This came out of my tank. The float was glued to the bottom.
First 3 positions are for full, half and empty.
It's a simple variable resistor except the current flows through the gasoline!
Simple VDO design but not durable, thanks to contacts and plastics used.
Here's where most non-rusted senders fail: tender connection at rivet.
The wiper arm is a spring steel so it stays in contact and wears little. It w...
Another nasty path to ground. Still a mess after a lot of cleaning.
Here's another example of how the resistor windings wear down and break.