Question for electrical gurus
 

What causes the wipers to return to rest after the switch is turned off. I'm tossing around the idea of grabbing a wiper module from a random junkyard car (not an rx7, since they're all bummed, and any good ones are expensive) and retrofit it to work with my system. Pretty much what I'll have is the module in some isolated location (probably under the dash) with the selector switch in the same spot. I just need to know how the switch knows when to cut power to the wipers to turn them off and bring them back to rest so I can properly modify the system. Is there a sensor on the wiper motor, or is it something like a finely tuned time delay?

Thanks

Relay #2 has probably gone bad in the wiper switch. You can fix it yourself. Part number G6C-2114-US-DC12 made by Omron Electronics Inc. Mine was doing the same thing. Also, it only worked on middle speed. Thanks to Icemark's writeup (also a different writeup at http://www.rotorwiki.com/index.php/Wiper_Switch_Fix) my switch works perfectly.

From Howstuffworks.