SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

I am replacing a controller in my garage. I took the old one out without taking a mental note of how it was wired because I thought this was a simple swap-out. When I go to put my new one on I realize I have a set of +/- ac wires that I don't know what they are for. The old unit had a 24vac transformer that was plugged into a wall receptacle and there are the expected 8 colored wires for my 7 zone system. But...there is also that set of ac wires coming out of the wall next to the colored wires.

Any ideas what this could be for, I can't figure it out. They aren't hot. Looking at my old unit I can't see where these wires were hooked up, but I know they were.

The old box was Weathermatic LawnMate7, the system is about 15 years old.