i have a 1955 210 2dr sedan. There was no wiper motor with the car at the time I bought it. I have been doing a two year frame off on it and am now in the process of wiring. I have a 55 chevy wiper motor I bought at Pleasanton goodguys swap meet. It works fine. My question? When I ground the motor, and supply 12v to the lead the motor works well. there is a sliding lever that moves horizontally, what is that for? It appears it needs a choke type push pull lever. Is it needed? Thanks from a wiring newbie.