I have a client that has an exisiting system and they would like a rain sensor installed. I haven't installed a sensor before but that seems easy enough. My problem is this, the clock is a 6 zone clock and all are wired to the 6 valves so there is not a terminal left for the hot wire to the sensor. My question is, can I piggy back a valve terminal with the sensor and will it work properly? Or am I way off here? How do y'all feel a bout sensors in general? Thanks!