interesting gauge wiring

[ruler]

I installed gauges on my truck this weekend and learned an interesting thing. The transmission gauge has to have a separate ground or it will read hot and scare the crap out of you. I also messed up some fuses and made a huge mess. I also bashed up the little brass bead inside the turbo gauge and would like to know how to get another one. I am installing exhaust next week and am wondering how much trouble that will be.