I have a 1992 F150 300 5-speed 2wd. My wipers only work on high speed, and only wipes once and returns to the parked (off) position on the windshield. . I have to twist the stalk every time I want to have the wiper go across once. GREAT conversation starter, especially with a manual trans.
I have a 1990 F150 for parts but of course it has different switches, and I also have a 1996 Ranger for parts.

 

I'd start with the multi function switch on the column, then there's a wiper control module behind the glove box (the thing that should click when you move the wiper switch), it's usually to the right of and kinda behind the RABS control module.
Sounds like the motor works, which is a good thing.

 

My 1993 has a similar problem except that sometimes on delay, it will work intermittently (like there is a loose connection somewhere).

How does one test the module?