@Gene I know this is an old thread but your hint about the rain sensor just saved me a lot of grief. We had a very old rain sensor in our gutter that hadn’t been used in well over a decade. It wasn’t; used by the rain-bird controller in the house when we moved in and it wasn’t; used by the Rachio 3 that replaced it. It was in my way so the last time I cleaned that gutter – about 2 weeks ago – i removed it by simply cutting the two-wire strand. Had no idea my common was running through that thing.
Anyway, thanks for helping out!