BiggDadddy

Anyone know any specifics about adding alarm sensors to the OEM system? I've seen some info about tapping into the hood switch wiring for a shock sensor but I can't find any info in how it's wired. I'm looking to put a contact or tilt sensor on tool box door, basically a N/C switch. Or maybe if when the alarm is activated there's a line that energizes that I could tap into to activate my own relay driven alarm???