I think you are thinking of the wire coming from the key lock switch, and that is a ground signal.

Right, that _is_ the one I was referring to. I take it you're thinking of the inside rocker switch...?

Also, if you use the one from the key it will disarm the factory alarm, if you so desire.

Well, yeah, you have to ground that to disarm the factory alarm or else it starts honking as soon as the engine starts. The problem is that that wire also unlocks all the doors at once... which I think is where I came into this discussion...