Problems with my 88 Marquis wipers
 

My windshield wipers have totally inconsistent patterns for if they work and how well they do. Sometimes they'll work like normal, sometimes they do nothing no matter what, sometimes they don't work on the "int" (1st) setting but seem fine otherwise. Sometimes they'll appear to be working on the low setting at first then cease function while driving. However, the washer fluid will always pump regardless of what the wipers do (or don't do)

I actually found a brand new OE wiper switch from NOS parts and installed it, they are behaving exactly the same as with the previous switch. The switch relay is clean. My only speculation is maybe some ground somewhere? But I'm not sure, I don't have a lot of electrical experience. Any tips would be great.

Thanks!