1978 El Camino, Testing Fuel Sending Unit and Fixing Rust

1978 El Camino, Testing Fuel Sending Unit and Fixing Rust. Here I am checking that the fuel tank sending unit and float is working correctly before I install it inside the gas tank. What I found out is that the gas gauge reads too high and this is being caused by a corroded connection with the ground wire to the body. That causes more ohms to be signaled to the gas gauge thus giving a higher reading on the gas gauge. This is not a problem with the gas gauge or the fuel sending unit. it's a problem with a dirty ground connection to the car frame from the ground wire coming from the fuel tank sending unit.