To add to what bigb56 said, check the ground that is bolted to the firewall above the hydroboost. Mine broke and caused problems with wipers. It even made the truck quit whenever I turned the ESOF switch.

 

I know this is an old thread but hoping this helps others. This is what I found on a 2003 Ford super duty to fix my issue after replacing the wiper
motor and turn signal stalk didn’t fix it. Note that both the wiper motor and windshield cleaner stopped at same time.

i found the green high current 12v wire had an open wore through where the wire met the sharp edge of the fender well. There are 4 large connectors on fender well that interconnect the wires from in the cab to the other parts of the truck. The one furthest towards the front of the truck is the one where the green power wire for wiper motor is plugged.
I ran a new wire between the open and moved this connector off of the fender well so this wouldn’t happen again.

 

exact same thing happened to my 2004 f250 gasser thanks for the post

 

I posted it in case it helped someone else so glad it did help you.
That’s the beauty of these forums , they’ve helped me so much .
cheers