C1 - '59 Fuel Gauge Wiring Issue

[Brad K.]

On my '59, my fuel gauge seems to be "on" all the time even when the ignition switch is in the "off" position. When I shake the car the gauge seems to "rock" when the float is rising up and down in the tank even when the key is in the "off" position. I'm sure this is the reason why there is a drain on my battery when the car sits.

I installed a new wiring harness when I rebuilt the car. Is there a short somewhere? Are the leads reversed? Is there a grounding issue? What else might it be? Those electrons are sneaky. The only thing I'm SURE of about electricity is that when I tie a knot in the wiring, the electricity can't get through!

Before I tear into it....where is the first place I should look?

[John H.]

Re: C1 - '59 Fuel Gauge Wiring Issue

Brad -

The fuel gauge and the temperature gauge are both fed via 18-ga. pink wires from a splice in the harness that's fed by a 14-ga. pink wire from the ignition switch - common feed of switched ignition power for both gauges. If the fuel gauge is getting power with the ignition switch "off", the temp gauge should too. Does the temp gauge reading change with the ignition off if you disconnect the sending unit connector? Then ground the sending unit connector? If so, could be a bad ignition switch, or the 14-ga. pink wire at the ignition switch is mis-indexed in the connector and is getting battery power instead of switched ignition power.

[Brad K.]

Re: C1 - '59 Fuel Gauge Wiring Issue

John,
Thanks for the solution.....All my friends here had me pointed in every direction OTHER than the ignition switch! I simply moved the 14ga wire to the other unused terminal on the switch and the problem went away.

Thank you for the excellent troubleshooting and thanks for serving us all on this forum!
Brad