Problematic Fuel Gauge Wiring

[sixpointsixliter]

Hello! My name is Carl, I've just joined and have been browsing the forums for awhile and am really enjoying the atmosphere. I'm not exactly sure weather or not I'm posting this in the correct location, but using common sense I think it fits.

I have a 1977 GMC Jimmy high sierra 6.6L I've torn out all the electrical in it and am in the process of redoing it. The stock Fuel Gauge has three terminals in it which connect (using some crazy metal backets) to the circuitry on the instrument panel. Well...you see...I have removed that and I've now stuck myself in the classic "which goes where" situation.

I've just installed a new gas tank/sending unit/ straps, and have made a new ground and ran a new signal wire all the way to the gauge up front. I believe it requires a 12volt+ a chassis ground and signal wire to the sending unit, but have no idea which way, and don't want to get it wrong for fear of sticking 12v to a grounded gas tank with 31 gallons in it...

Any help would be greatly appreciated, Google and my Haynes/GMC maintaince books haven't given me exactly what I was looking for.





Video is about 6 years old but...
https://youtu.be/lwBwetg2Uzo