1998 Chevy Astro winshield wipers

Hi:
It could be either the switch, the motor, or other problems. What I need you to do, is when the wipers don't work, unplug the motor under the hood and see if you're getting power to the motor. If you are, replace the motor. If not, you should follow the power lead back to the switch to check for a broken or damaged wire. If the wiring is good, replace the switch.

Joe