Weird windshield wiper gremlin

[MountainGoat1966]

Or maybe the space aliens are messing with me again.
I installed a used intermittent wiper control in my 83 C20 and if I let the truck sit for a day or two without turning the key on, OR if I unhook the battery for a few hours when working on the truck, the wipers do one sweep when I turn the key to the on position to start the engine.
I'm guessing it has a bad control module and I should just go back to the original wiper switch .....At least it worked normal (sorta) giving me slow wipers and the high speed is just a slight tad faster, barely enough to matter.
Neither switch gave me slow and fast wipers, is the same with either switch installed.

[Your41Plague12]

I'm not sure about why they do a sweep like that. So it never did it with the factory dash switch, but once you installed the intermittent dash switch and the box under the dash it began to do it?

And as for the wipers being slow, that's just the way these old tanks are. My 83 had two speeds, slow and slower. My neighbor's 55 chevy wagon with factory vacuum wipers has wipers that move twice as fast. It's pretty pathetic.

[MountainGoat1966]

I went for a drive today, and twice during the drive the wipers would do one sweep on their own.
Never did it with the original switch.
Guess I will put the original switch back in and live without intermittent.
When I still had my 66, it had two speeds, slow and fast and both worked.
I wonder if a motor from way back then would work on the 83 .......