Ok, I have it installed and have power to it.

I need to know which wire to tap to get lights to come on the gauge.

Also why would to gauge read below 0 at idle?

Thanks as I am trying to install this as I am typing.

 

Go check the how to section, there is a excelent write up on how to install a Defi boost gauge it should be the same on any boost gauge. Its reading below 0 because the car creates a vacuum and thats what your looking at.

 

I already did that and it says to hook up to the green/yellow wire and there is not a green/yellow wire there.

 

Got it. It is installed now.