@blakeyoung - my guess is the pink wire is going to the former rain sensor. I’d try the system with the pink wire disconnected and see if it still works. If the system still works, I’d leave the pink wire disconnected. The reason is that there is 24 VAC going somewhere - and if it was where the wire was cut in the yard, I’d hate for it to short against something and pull too much current through the Rachio and maybe burn out a component. Just my $0.02.
