Switched positive or negative?

[Qship1996]

I have a 1996 Infiniti Q45 that I would like to add a heavy duty wiring harness/relays for the headlamps {H4 low/high and 9005 high that light both bulbs on highbeam} the question I have is when ordering a harness, they ask if vehicle is a switched positive OR a switched negative? How can I tell? I plan on using the osram 65/70 h4 and the 9011 HIR bulbs}- headlights are glass,not plastic.