The Stovebolt Site Forums The Shop Area The Electrical Bay 54 Fuel Gauge

After reading the posts on testing both the gauge and sending unit there is just one piece of info missing?
If the gauge is removed from the truck for bench testing would the contact pad on the back of the gauge that would normally be grounded via the body, play a part in testing?
My first thought with this not working correctly was if the gauge housing was not getting a good ground due to corrosion on the back of the dash.
Any thoughts would be great.

https://photos.app.goo.gl/dpUPTpllVbLZnF562

"Would the contact pad on the back of the gauge that would normally be grounded via the body, play a part in testing?"

If the actual fuel gauge itself is removed from the gauge cluster housing/body. The answer is Yes, the contact pad/plate is the ground for the fuel gauge.
The fuel gauge pad/plate transfers the fuel gauge ground to the gauge cluster housing/body.
When installing the fuel gauge into the gauge cluster housing there is a insulating pad that prevents the hot fuel gauge terminals from touching the gauge cluster housing.

"The gauge housing was not getting a good ground due to corrosion on the back of the dash."

That could be a possibility but uncommon.

Testing the fuel gauge when installed in the gauge cluster housing is preferred.
The Ground wire then can be attached to the mounting plate..

xfiles

Thanks jorb for clearing that up.
I will now be able to test it correctly on the bench.

Fixed
spun the dial 360 deg. Loosened it up and now works fine.
Follows the tank float to perfection.
Dont even try to explain that.

I have a related question, 1946 Chevy pickup. I just had my fuel gauge rebuilt to 12v specs and I put in a new sending unit. Installed it and it just moves about a millimeter when I turn the key. The power wire I ran to the gauge started to smoke up on me when I was driving so I had to pull over and disconnect it. Any ideas what I should do? Thanks

Sounds like the power wire you ran to the gauge, Shorted out and is touching ground.
If you know how to use a digital voltmeter set it on the lowest ohm setting.
Then touch the two test leads together, meter should read zero.
Disconnect the power wire at the gauge.
With the ignition switched off, touch one test lead onto connector of the wire that you just disconnected.
Touch the other test lead to the body/dash of the truck.
If the meter reads zero you have a short, replace wire or find the source of the short in the wire.
1946 Truck Wiring.... in Pdf format

Thank you for the info. I’ll try it.