2000 Monte Carlo Wipers

I have a 2000 Chevrolet Monte Carlo, automatic with V6 3.4L engine. It has 120,000 miles on it. 2 years ago, the windshield wipers started to occaisionally stop in the vertical position and this summer, they do it everytime. They still work, just stop vertically now matter where they are when I turn them off. Someone told me to try a new wiper motor pulse board. Could that be a problem or is it always the motor?