Windshield Wipers can't find home position

...or at least that's what I think is happening.

A few days ago my windshield wipers stopped working properly. I have observed the following:

• Turning the wipers onto the intermittent setting does not result in expected operation; the wipers operate continuously on "low" setting, regardless of the intermittent delay I select on the dial

• Turning the wipers onto the "low" setting results in expected operation; wipers operate continuously at normal speed

• Turning the wipers onto the "high" setting results in expected operation; wipers operate continuously at high speed

• Turning the wipers off does not result in expected operation. The wipers will operate for another few cycles (two or three) and then stop somewhere randomly in the middle of the windshield

• Pressing the wiper lever up to the "mist" position and releasing it does not result in normal operation. The wipers will operate for three to four swipes and stop randomly in the middle of the windshield

I am interpreting all this as the wipers suddenly being unable to determine where "home" position is (therefore unable to notify the computer when to be turned off) and a central computer control safety net of sorts finally kicking in and killing power to the wipers after x number of seconds have passed with the switch in the "off" position and the wipers still unexpectedly running.

Has anyone else experienced this problem and can you point me in an initial troubleshooting direction?

Thanks,

-Chuck