95 Montero. 170,000 mi. 4-WD. While driving around 30 mph., engine quits. Just after I turned on semi-functional air conditioner. Next, it would not turn over until I jiggled 4-wheel drive shifter a few times. When it did turn over, engine did not fire. Also, gets sluggish after a few tries on starter and nearly killed new battery. Two more things. After doing 4WD on a beach, noises from the front and noises in reverse if any version of 4wd selected for several months. Also, just had alternator and new battery installed. No warning light signals or other unusual signs. Anybody have any ideas and how to fix it??

 

If it started this right after the battery and alt were replaced I would check all connnections at the alt and battery terminals.