'94 Explorer

My Explorer will not start or run well after an evening of raining. Any ideas?

bad spark plug wires, distributor cap or coil

Got full coverage? I suggest putting it in neutral and allowing it to roll off a cliff. If that isn’t an option, I would suggest checking your battery for currosive build up. I know I had problems with that because the Ford mechanic put a battery 2 sizes too small into it. The currosion usually caused the connection to the battery nodes to become obstructed to the point where no connection was made at all.

If you don’t remember when the plug wires were last replaced, I would start there. The coils distributor cap etc are next, or why not do it all at once. Likely the plugs are due for replacement as well so you should do those also.

This may not do it, but it is the most likely issue and if it has been a long time it cost nothing to do it since you should do it anyway. It many even pay you back with a little better mileage.