The initial problem I was having was the unit would "dance" at the top of the stroke, and then turn itself off. I tested the Top Limit Switch, and it seemed Ok but I replaced it anyway. No change, still would not work correctly. I then inspected the chain and gears, and all were good. I then replaced the tilt door safety switch, and the foot switch. All switches seemed fine, but I had an old unit available for parts.

During the process I had the foot pedal removed, and I noticed the unit would work perfectly when the door safety switch was disconnected. I didn't think it would run at all, but it did. I then put it all back together, not realizing the foot pedal actually presses the switch in all the time (contact). The unit would not operate.

I'm left in this really strange place, where it will operate fine with the door safety switch removed, and the actuator pedal removed. Something seems to have reversed the polarity or something, where it works fine with momentary contact, instead of turning on with momentary disconnect. I rechecked the wires on the Top Limit Switch, and everything is correctly wired by color.

I'm at a loss, and looking for ideas. Reading the Tech Sheet it mentions a Motor Centrifugal Switch contacts will cause it to oscillate up and down. I thought the Centrifugal switch was a start switch. If it runs fine with the actuator pedal removed and the tilt safety switch disconnected, I'm not sure how the motor could be the cause. With the actuator pedal removed, and the tilt safety switch disconnected, everything works correctly, including up and down, pack, etc.