installed new sending unit, from roberts motor parts

[michael.warshaw]

the problem is that my guage only goes to about 3/4 is the guage no good?

[desoto1939]

Mike:

In my 39 Desoto the dash gage could also be adjusted. There were two point that got heated because of the sending of the poser back from the tank gage. Look in you parts repair manual on your specific car and read up on the dash gas gage it might tell you more not sure on your ca but thats how it works on my 39 Desoto.

Rich Hartung

Desoto1939@aol.com

[alan32433]

Your gauge probably needs calibrating. If its like my 48 Desoto, there are adjustment arms on the gauge itself. You'll have to remove the gauge and the sending unit and set them up on your workbench connected to a 6v battery per schematic diagram. Calibrating envolves setting the float unit as if it were empty to adjust the E reading, then setting the float as if the tank were full to set the F reading. You will be moving the float lever up and down to do this so you'll have to figure out a way to hold it up for the full reading. It takes several attempts because each of the adjustment arms has some impact on the other. After a while and several adjustments to each arm you should get it right. You have to also know that the circuit is actually a small heated thermostatic spring and the reading takes a few minutes to go from full to empty. It was designed this way to prevent gas sloshing around in the tank from resulting in an erratically moving gas gauge. So be patient. When I did mine, I measured the depth of the fuel tank to determine the actual position of the float when empty and full. Thats the only way to get it right. When you reinstall the gauge, be careful, you can easily knock the adjust out of calibration again.

Alan

[michael.warshaw]

thanks