VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 Fuel Sender

I'm in the process to purchase a new fuel sender from Fstation.

Question:

How can I test the Fuel gauge to see if it is working?
I've taken out the old fuel sender and tested with the arm up and down but nothing. I suspect the sender is shot but want to know what other method I can use to see if gauge is working.

Thanks

To test both units on the workbench, hook a jumper lead to the terminal on the sending unit and the other end of the jumper lead to the terminal on the back of the gas gauge marked "tank". Take another jumper lead and attach one end to the sending unit case and the other end to the gas gauge case. Using a third jumper lead, connect one end to the terminal on the back of the gas gauge marked "Ignition" and attach the other end of the jumper lead to the positive post on a six volt battery. Finally, take yet another jumper lead and connect one end to the negative post on a six volt battery and the other end of the lead to the gas gauge case.

Move the sending unit float and arm up and down and the gas gauge should read as the arm goes up and down. Also, if you have a battery eliminator, you can use that in the place of the six volt battery.

Done exactly that Junkyard dog but no luck.

Is there any other way of testing without the sender unit? The sender unit look suspect. I have a multimeter if this could be helpful.

Hi Junkyard dog,

After wiggling the sender unit I got life out of it. It works 100%

Interesting the part where one connect the negative to the body of the sender. My tank lies in rubber strips between tank and metal strips holding tank to body. This means that the tank is isolated from the negative body ground to complete the circuit. The rubber strips are there to prevent chafing.

Do you guys think I need to add a ground strap from the sender body to the body? Makes sense though.

The tank and sender need to be grounded. Safety on the tank and for the sender to work it must have equal ground as the dash gauge.

The sending unit is basically a 30 ohm wire wound resistor with a wiper arm (potentiometer)to ground. Mine was riveted together, I drilled out the rivets cleaned it throughly with alcohol, make sure the wiper has good contact and put it back together with screws. FS sales the cork floats also. Easy fix and keeps it original.

If you are going to rebuild the or repair the sending unit I suggest replacing the cork float with a metal float. They are available from the Filling Station part number SA-99. All you have to do is take a piece of coat hanger wire, make a loop in one end, wrap it 3/4 around the float, match the bends, use it to replace the wire on the sender and crimp the end to hold it in place. I have done several that way.