I have a 92 Bronco. When the key is in the ACC position the windshield wipers work perfectly fine in all positions (intermitent, low and high). But when the key is in the RUN position they only work in the low and high positions. They only move once when I set it to the intermitent position. I would appreciate any help

 

sounds like something may be in a bind as in when you turn the key it's hitting something