will a bad wiper switch mess with the highbeam switch and headlights? strange issue..

[1981Stepside]

The problem COULD be in the stalk, but I doubt it. I had the same problem with the headlights in my 81. (I've swapped the column with an 85 to get the wiper controls on the stalk.) It turned out to corrosion on the terminals of the headlight harness. Also, the previous owner had converted the headlights to h1/h4 lights from the sealed beams and it was the adapter harness that was corroded.
As far as the wipers, I had an issue with the delay function and had no park function or spray which also turned out to be corrosion on the terminals. If this is what's creating your problem and you're careful, you can remove the brass terminals from the plastic housing, clean them with contact cleaner and give the surfaces a light scuff with sandpaper to ensure a solid connection.