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!

 

More than likely you need to put on some new battery terminals. It could be the battery. possibly the ground from the battery to the engine is loose. Just follow the ground cable from the battery to the engine, I think its bolted on near the a/c compressor bracket.