I am using a Hunter Rain Clik Wireless rain sensor. I was experiencing the described continuous sensor activation / deactivation issue. There are two (2) yellow wires from the Receiver that are connected to 24V + and 24V -. If your rain sensor is cycling as described above - simply reverse the two yellow wires to the opposite polarity. After rewiring, go to your rain sensor and hold the switch (spindle) down for 3 full seconds. Your issue should be resolved with this change in polarity wiring.
Art O.