Brothers' 2011 6.4 has a problem with the wipers. Wipers work on any constant speed, but do not work at all on any wiper delay speed.

My questions:

1. Is there a separate delay module for the wipers?
2. If not, what controls the delay?
3. Is there a separate fuse for the delay?
4. If the wiper delay is controlled by the GEM module (or equivalent), how do I diagnose it?
5. Is there any other causes that anybody can point me to?

I own a 2001 with a 7.3 in it, so I have no experience with the truck is question.

 

He is out of the 36/36? This was a common problem with the MFS in prior years, figured they had it fixed by '11 though.

 

Well out of warranty. He has 240,000 miles on it.

Do you have any idea what the problem is or could be?