Use low-voltage insulated cable approved for burial (usually AWG-14 or -18) to connect the timer to the control valves. You will need multi-strand wire with enough wires for each valve plus one more to connect the valves to the timer. (So, if you have three valves, you’ll need four-strand wire.)

If there’s a possibility you’ll add on to your irrigation system, use wire with extra strands so you can add valves without having to rewire the entire system.

After connecting the wires, run them underground to the timer. Make use of sprinkler trenches where you can, placing wires underneath the pipes and loosely looping around each valve and bend in the trench.

Run the wire above ground when you get to the timer, and secure it to a wall or other surface to keep it from getting snagged. Make sure the timer is not plugged in while you are wiring.

Two wires run from each control valve; connect one of them to the common wire that runs to each valve and the other to the desired station number. Attach the timer and then connect the common wire to its screw terminal, remembering which circuit uses which station.