My 97 TJ windshield wipers cannot be turned off when it is damp outside. Overnight rain, fog or just the morning dew and the wipers can only be turned off by putting the stalk between positions. This works until you hit a bump. Once the car dries out they work fine except that they will not park. I figure it has to be the motor or the control. Anyone else have this problem and what did it turn out to be?