Testing gauges with new voltage limiter

GRRRRRR, You have a shade tree repair at the circuit board contact pin where 12 volts is. That is totally not needed with a replacement regulator. If the head of that little bolt contacts the housing behind the board, you have a short circuit. There is very little relief behind the board there. Take that screw out and toss it. Take that wire out of the round harness connector and attach it directly to the regulators 12 volt wire with male and female spade terminals. You dont want or need 12 volts going into the fuel gauge anyway.
Internal toothed washers and 10-32 hex nuts just like what is on you amp gauge posts are available at home depot in little orange packages at about 78 cent for 6 to 10 pieces. I have put the ring terminal, toothed washer and hex nut on top of the speedy nut.
Those little screws that attach the board to housing do provide ground paths for light bulbs but they are in piss poor threads , easy to strip out, and really too short for added ring terminal and toothed washer. An actual dedicated ground wire attached under the dash somewhere will serve much better. Again male and female spade connectors so the added ground wire will unplug like most everything else.