Question
Jim, I just added two new zones or stations to my existing system.  I bought a 6 zone orbit outdoor controller to replace my Rainbird ESP-4.  Unfortunately I labeled all my wires with bad ink and rewired all 6 valves.  The problem is how do I hook my valves to my pump relay and my controller (specifically my MV or pump and common wire?)I hooked all zones to appropriate place on controller but but have tried various wiring to get pump to come on.  I hear valves click when I try to run system but pump no work.  Thanks, Derrick

Answer
Hey Derrick, I hope this helps. Basically the pump relay will have 2 wires that run to it. One of these wires will hook to the MV or pump start terminal, and the other wire will hook to the C (common) terminal . It sounds like the valves are wired okay, the relay might have a separate common that you need to hook to the common terminal, besides the valve common. In other words you might need to have more than 1 common wire hooked to the common terminal. The other thing to consider is if the relay has gone bad, or the wire to the relay has gone bad. What you could try doing, is with a volt/ohm meter, first try checking the voltage to your MV or pump start terminal when the system is on, just to make sure the controller is working properly. Just touch the negative lead to the common terminal, and the hot lead to the MV or Pump start terminal, and see if you're getting between 22 to 26 volts. Next thing I would do, if your voltage is good at the controller, is by trial and error, hook different combinations of wires onto the controller, and check your voltage at the ends of the wires where it hooks to the relay. Let me know if I can help you out anymore, thanks and have a great day.