TKing

I had a Honda that did *exactly* that a couple of times and it turned out to be the key cylinder. That would be my guess here.

I don't have any specific knowledge of this system, but it seems to me that the Xenons are tapping power from the wrong circuit. They are loading down that is not designed to be a source for that much current and the result is a severe voltage drop that all the other devices on that circuit are subject to. Is it possible they were electrically incorrectly installed?