1st i lubed my trico vacuum wiper motor with Dot 3 as i've read that works well. Next i hooked up a vacuum hose to one of the two ports on the side of the motor. when i turned the switch, the mechanism rotated and stopped. when i turned the switch again the mechanism would rotate back to the other side, but the mechanism didn't keep rotating back and forth as i was hoping. do i need to hook up 2 vacuum lines to the two ports on the side? what is the center port for? any help is appreciated.
