I recently replaced a valve and have just added my Intermatic valve actuator back on. With the cover off of the actuator, I am able to adjust the cams to get the valve actuator to control the valve to precisely the right locations for both spa and pool. However, once I put on the cover, even if it is quite loose, the valve actuator will continue to turn the valve past the limit switch when going in the CCW direction. Once I remove the cover, everything returns to normal.
I have looked at this for hours trying to see if there is any interference and I simply can't figure out what is going on !!