2 Speed Wiper?

[Deereman]

My 71 C50 hasn't had working wipers, I don't know why but someone had taken the arms off and left them in the cab. I ended up not having power to the wiper motor from the fuse box, the cluster feed is also like this because of rust in the panel. I ran a new wire with an inline fuse from the key to the wiper motor hot. I then wanted to test the wiper switch but pulled the back off of it when trying to disconnect the wires. I got a universal replacement switch from the local parts store and it wipes and I can hear the washer pump try to pump but I only have one wiper speed. The old switch had 3 positions and the knob would push in. What is supposed to regulate the two speeds? Or do I have a single speed motor?