Wipers are a solder joint problem. The connector on the wiper control module under the hood is notorious for failure. If you'd like to take it on, it's really not that difficult. You unplug it and remove the control module from the housing. Most of the time the fix is to simply reapply some heat to the solder joints on the main connector. Make sure your soldering iron is very hot to begin with and then touch each pin. As soon as you see the solder melt, you're ready to move to the next pin. It wouldn't hurt to have a coil of rosin core solder and some flux paste handy in case you need to doctor any of the joints with a little more metal. The flux is needed to clean impurities from the tip of the iron. You must only use rosin core for electronics. There is acid core solder on the market, but that is only used for copper pipe fittings. One other item to have by your side is a small damp sponge. The sponge is useful to wipe off excess solde from the tip of the iron.