IF the wipers have a fuse it'll be under dash on the drivers side in the fuse panel. I think that there might be one, but 99% of the time it's going to be a motor issue. #1. Before you condemn the motor check the ground tab. You can bypass the ground tab with a test wire and see if it comes back to life. #2. If you decide to replace the wiper motor, please do not buy an A1Cardone or cardone remanufactures units. They are junk and we will no longer use them at the shop. ACDelco doesn't seem to manufacture them anymore so your best bet is to purchase a WIA brand new unit, Autozone sells them and they will ship to home if you don't have an autozone near you. Amazon sells them too.
One of the issues is the Cardone also manufactures a lot of the house brand reman units, for example NAPA branded Remaned wiper motors are remaned by cardone. So just steer clear of remaned wiper units please.
Also see these links for lots of wiper info. Even if your not interested in trying to rebuild your own wiper motor you can learn a lot from it, and there are diagrams further in on the threads.
The following pics and descriptions only apply (to my knowledge) to 85-91 SB wiper motors. I started with 3 motors and chose the worst one to rebuild. With it on a bench and no transmission connected, it ran at about 20% slow and a tad more more on hi. Keep in mind these are motors that are...
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Newer cars when there is problem with the wiper linkage the solution is to purchase linkage and replace it, but on these old trucks in most cases you can service / rebuild it. Though you can no longer get an entire assembly at your local auto parts store places like LMC do still have them, but...
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