My friend has a 1980 Pickup, when he got it the wipers didn't work and it had a rough idle, after a few weeks the wipers started working and the rough idle went away. So out of sight out of mind.
Just today the wipers quit working and the idle is rough again, wanting to stall at lights and just generally being a PITA.

He checked the fuses and they are all fine, has anybody dealt with this before?