I'm trying to replace one switch in a double gang switchbox with a new timer switch but I can't figure out the setup. There are two conduits entering the bottom of the box, one with a white and a green wire, the other one (which leads to a receptacle) with a white, a green, and a blue wire. At the top of the box there is one conduit (leading to a light) , with a blue and a white wire. All the whites are connected together with a wire nut, as are the two greens. The blue to the receptacle is connected to the bottom screw of one switch, the blue to the light is connected to the bottom screw of the other switch, and a pigtail from the nutted greens goes to the top of the receptacle switch then over to the top of the light switch.
The timer switch has a white (neutral) a black (line) and a blue (load). I tried it white-to-white, blue-to-blue, green-to-black. The timer display shows power, but neither light nor receptacle worked. I tried switching the green and blue. Same result.
According to your drawing, the switch on the right is for the light. You want to control the light with the timer, correct?
Leave the switch on the left as is, then connect the black wire to the green wire that went to the old switch, connect the white to the white wire nut group and the blue to the blue.