I connected my "G" to ground of my car. When I open the PS, I realized that the "G" wire just goes to the housing of the PS. My ps is mounted to the car with a metal brakets any way so it wouldn't matter is I use the "G" terminal or not. I ran it without hooking the "G" and it worked fine. I also hook it up and it did'nt make any difference. I also siliconed all of the heavy parts(coils, heat sinks, etc.) so it doesn't come of the board. I don't think this is necessary but I just wanted to make sure nothing gets lose with vibration. Caution-voids you warranty if you open it up!