I've spoken to a few people and it appears they are unable to locate the 07 Escalade electrical wiring diagram. Can someone advise if these are available and where?

My main issue is where the starter/kill wire switch is.

Where can I get the electrical wiring diagram for the $63K SUV I just bought?

I'm also running into a problem where no one wants to touch it to add an alarm.

Thanks for any help!