Wipers issue

Hi:

I have a 1992 Jetta.

1. The wipers have been not functioning properly. When I bring the wiper control arm to 'off' position from the '1-up' (slow speed) position, the wipers don't stop and continue in slow speed. When I bring the wiper control arm to the '1-down' (intermittent speed) position, the wipers still continue in slow speed (as if they are in the '1-up' position). Also, when I pull the wiper arm for the washer spray, the wipers should wipe for 4 cycles in slow speed, then stop, but they continue in slow speed even after 4 cycles.

1. The wiper blades make a 'snap' noise on the windshield when they are on the downward cycle, right when they turn to start wiping in the downward motion.

Any ideas?

Thanks,

AJ.