Is the problem with the wiper switch similar to the problem with 1st gen lighting switches? We have found that by shooting them full of Electrical Contact Cleaner (like 6 bucks from Autozone for a huge can) and working the switch back and forth for a bit, cleans the contacts up and gets them working again. No parts need to be removed to do this.
Might not apply to this issue, but I thought I'd throw it out there for you just in case.
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