Jeep Cherokee Wiper Problem

Jeep Cherokee Classic 1998 82,000 miles, 4.0L engine. Here is my Question. My wipers recently only work in the full speed position. When I turn them off, they do not return to the rested or off position. Now what is weird is that this has happened before and then everything returns to normal. Then when winter rolls around the cycle starts all over again. I know it might be the motor but hope it is not since I hear they are expensive to replace. Thanks for any help you can give me. I may leave a dontation at another time, this is my first visit.