Air vent actuators cycle at timed intervals. Ignition off, key removed, driver's door opened and closed to terminate the delay timer. Actuators in the air vents do a cycle every few minutes, it never stops. Why? Center console buttons have continuous glow. After a time interval this button glow should extinguish, the actuators should cycle once.

 

Have you scan the van for codes? I would unplug the blower resistor and see if the problem stops.

 

no codes, OBD gives no results

 

Solution found. Backlight glow, caused by cycling of occupancy sensors. If you leave something on either of the two front seats, you may cycle the detection. Realizing that the back glow was not there, I place tonight on the driver seat. Immediately the back glow came on. Remove the item from the seat, and a few minutes later the back glow turned off. Research online revealed that the bottom seat cushion has a switch embedded near the front edge. Both the driver and passenger seats. The electronics for this occupant detection is under the passenger seat near the front toward the center console.If you want to stop the drain on your battery, don't leave things on either of the two front seats. The circuit will continue to cycle and deplete your battery.