rosswilliamsz
DIY
I
I have been replacing certain wall switches with timers for outdoor lights. This four switch box has me stumped. The three switches on the left are all working properly. I am trying to wire the timer on the right. The hand-drawn diagram shows ALL wires within the boxes except for the grounds, which are all tied together. Specifically, I don't understand why black wires from three switches are tied together with a white wire from the fourth wall box. Any help on the proper connections for the timer would be greatly appreciated!