The wiper motor drives a short arm in a small circle, which drives a connecting rod that translates the circular motion into lateral crosswise back and forth action. That connecting rod connects to swing arms that drive the rotational studs to which the windshield wiper arms affix.

If your wiper arms still operate in unison, I'd turn on the wiper motor and shine a flashlight down into the windshield vent on the passenger side. You shoudl be able to visualize the assembly and identify what's moving and what's not. I'd guess that the connecting rod flexed enough to pop it off the ball stud on the wiper motor armature. If that's the case, pop it back on, and pull out the creeper for underside inspection. Three or four hours later, after a good nap, crawl back out and inform the wife that, by the merit of your hard work and incredible mechanical skills, you have repaired the issue. <img src="/forums/images/graemlins/mrt.gif" alt="" />

Randii