wiper switch (or motor) in a '78

[willett]

first off hey everyone, i'm stoked i found this place

now the question:
i bought my '78 about a year ago and the high-speed position for my wipers never worked. ok. i robbed a switch out of a '79(i think) and tossed it in with the same problem... no high-speed setting

am i just unlucky to get another bum switch, or am i not digging deep enough into the problem??