When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
So basically your Explorer dies as soon as you put it in Drive? I'd suspect either a low battery (that drops the system voltage too much when the engine is put under load and the brake lights are on) or you may have a vacuum leak that causes the engine to stall when a load is placed on it. If you very carefully, and preferably in an open area, give the truck some throttle when shifting to drive while firmly holding the brake pedal, will the truck remain running? If so, does it run rough under load?
When is the last time the truck had a tune up (spark plugs, plug wires, air filter, fuel filter)?
-Rod