My gate partially closes after opening or reopens partially after closing.

This is almost always a limit adjustment issue or a problem with bracket placement. Please review your installation manual. Remember that on pull to open gates (gates that open towards the property instead of towards the road - see PDF below for a visual) the open gate position is determined by bracket placement with a fully retracted operator arm.

When your gate, after it opens,  closes back partially this is what we refer to as an obstruction. The unit’s internal safeties were triggered because the arm was (most likely) not physically allowed to return to the fully retracted position. The most common cause is that the arm was not fully retracted when the gate bracket was installed. 

Example of an open gate and fully retracted control arm.

Gate Obstruction

Click the picture below to view the video of a pull to open gate where the gate bracket was placed wrong, so the gate in some manner is being physically restricted or the arm is making contact with the gate. 

If an obstruction is occurring at or near close on a pull to open gate, the limit is either not set or was set incorrectly. Assuming that the above is not occurring or has been corrected follow the below procedure.

For push to open gates the closed gate position is determined by bracket placement with a fully retracted operator arm. On a push to open unit the open position is controlled electronically by the below procedure. Please see the PDF below for a visual.