My 94 which now has about 137k on the clock has recently developed a noticeable "clunk" when the wipers are operating. The noise occurs when the blades are at the bottom of the glass and rising, not when they're vertical. It's much worse when the windshield is dry (interval set too long).

What part fails first in these systems?

I took a look at the wiper system in the parts catalog pdf and *whoa* I've never seen a setup like that before.

Anyone have any experience troubleshooting the wiper system?

 

grab the driverside blade and try to pull it up the windshield, anything more than 1/4 inch of play would mean the linkage is going out

 

Could also mean that the nut that holds the base of the wiper arm to the splined shaft came loose, letting the arm slop back and forth.
Had that happen to me more than once. Pop the cover off and see if your nut needs to be tightened.

 

mine does the same and its the rubber bushing that holds the wiper motor in place. id pop the cover off and see if you can move the motor up and down. that will tell you a lot