Gas gauge not working? I think I fixed it.

I hate to be the bearer of news, but what you have done here is re--invented the wheel. There's many before you on Al Gore's internet who've installed 5V regulators

But.......you did discover, figure out, and fix it yourself. You get a lotta points for that.

You missed the point, the temp gauge needs the 5vdc regulator, but I put a 6 (six) vdc regulator on the gas gauge. The regulators are side by side.

The fuel gauge needs the extra voltage to kick it in the butt. It is only one volt more but that one volt is 17% more than it was.