Trouble with wipers

i own a 1989 f150. a couple of weeks ago i was driveing it in the rain and wipers would stutter if i put it on one of the faster settings but if i left it in the slowest position it ran alright. i got it home ok and then left it for the night. went back out the next day and tested the wipers and they wouldn't even turn on. don't hear any clicking or anything from the motors. i was wondering if you guys could help me out with it. is it just a loose wire somewhere or is the motor burned out? i checked the connections at the wiper motor and they seemed fine. any help would be greatly appreciated. thanks.

First make sure wiper motor is tightly bolted to firewall as this is it's ground. It could be a little loose and when on low speed looses ground. If this is not the prob, and you checked all wiper wire conection and fuse's then it is the motor it's self.