Firestorm, take the cover off of the wiper module and resolder all the connections. All you have to do is get the solder hot enough to get it to puddle. It's best to do it off the truck. What happens is the cold solder joints vibrate enough that the connections crack and no longer function correctly. I have fixed 3 or 4 just by resoldering the connections. You'll need a good solder gun for the large areas. A solder pencil is too light to get it hot enough to melt the solder.