I am sort of a back yard mechanic but this one has stumped me good.

My truck is a 2002 Dodge Diesel 2500 4X4 and the windshield wipers quit about a month ago, they wont do anything and I cant figure it out, so far I have;
checked the fuse, swapped out the relay, bought a new motor-still didnt work, took it back, bought the wiper switch that goes on the column- still dont work, too that back!!!
I am at my wits end, Please Help!!!

any questions I will watch and repost if necessary.
Thanks