The Stovebolt Site Forums The Shop Area The Electrical Bay Troubleshooting Gas gauge on 1937 chevy pickup

I was wondering if someone could help me with the best way to troubleshoot my gas gauge on a 1937 chevy 1/2 ton pickup I don't know if I should start at the sending unit on the gas tank or in the cab at the gas gauge?

Mike , fixing one problem at a time!!

Here is the simple idea behind gas gauges,

1- voltage is feed to one side of the gauge from the ignition switch, 6v if stock, 12v with reducer to 6v if altered.

2- from the second post on the gauge, a wire or series of wires, run to the sending unit in the tank.

3- the sender in the tank has a variable resister built in it that changes resistance depending on the fuel level, 0 to 30 ohm

4- the fuel sender is grounded to the tank. The tank should be grounded to the frame.

5- the sender varies the amount of ground circuit going to the gauge, so unhook it and the gauge reads empty, ground the wire and gauge reads full.

You could have a bad ground wire at the tank, bad sender in the tank, bad gauge, poor connection at the gauge, bad fuse.

Let us know what it is or is not doing and someone here should be able to fix it. Joe

Hi Mike, this has been discussed adnauseum in the past in several of the forums. Doing a search of the forums using "gas gauge" in the search box will net you hours of informative reading.