I can't help with your problems, but you might be able to find a wiring diagram at one of the links in the Online Repair Manuals guide.
There's a Power Distribution and other wiring diagrams in the Auto Repair Reference Center database that I can get through my local library, for example.
There's also a 17 page TSB No. TS 005 08115(B) that is used to diagnose Sidekick security systems. Maybe you can get a copy of it from a dealer?