I saw alot of threads on it, but no one came back after they fixed this issue. My wipers only move 2 inches and only work on high. I have tried two different wiper motors and circuit boards.
Wiper Switch is new.
Multifunction switch is new.

 

It sounds like it's pulling them out of the park position, and then going right back. Have you put a multimeter to the plugs to make sure the switch is doing what it's supposed to be doing? Even if you put a new one in, the wiring may be damaged somewhere between the switch and the motor. Did you just put a circuit board straight in, or did you put new capacitors on it first? It could be a broken solder joint on the board that isn't visible, or you could have just had bad luck and pulled a second board with and identical problem to the first.

 

I’m having the same issue with my 87 Camaro. I was in the process of changing out the wiper washer pump, only to find out the contacts inside the module were broken. So I ended up replacing the whole thing, and now I only have high and no intermittent wipers, and the other wipers only moved 2 inches. I cannot figure out the linkage issue. See my attached video.

 

Mine ended up also having a short in the motor connector.
I turned it on and just bent 1 at a time forward and back and i think it was the gray one I can't remember but it started working.