2002 f350 remote start

I am installing a Performance Teknique remote start on my 2002 F-350 Powerstroke. I have a Pulse timer relay to make up for the wait-to-start light. The only thing I am missing is where is the negative door input wire. I am supposed to use this for the negative door trigger and negative dome light supervision wire. The positive is BLACK/ lt. blue at the kick panel but I don't know which one the negative is. thank you for any help.

As far as i know there is not a negaitve door pin in that car just use a relay to switch it from postive to negative. 85 to BLACK/ lt. blue 86 and 87 to ground 30 to negative input on alarm. That should cover it

Thanks chad, that is what I was kind of wondering if I had to do.