89 Montero wont start
 

I am experiencing a no start issue with my 89 Montero 3.0L. It started all of a sudden and kinda sounds like an electrical short to me. When I turn the key in the ignition... all power cuts off to the vehicle. It has to sit for a while with the battery disconnected in order for the vehicle to have power again. This is an intermittent issue and sometimes everything else works (power windows, locks, dome light) but it won't start, and sometimes NOTHING works, even with a fully charged battery. PLEASE HELP!