The fuse on ours was adequate. Thor had a batch of bad pumps on their first Axis/Vegas coaches. Since the fuse controls the wipers and washer it will fuse both whenever the washer is engaged. You can replace the fuse and not use the washer and then the wipers will work. Not a good long term solution though.
When it happened to us in early 2014 it was not a known problem like it is now, so it took more troubleshooting.
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