Question
My system has a Hardie Controller, a pump start relay, and a 1/2 hp pump. The system has always been reliable the for the six years I've owned the house (system may be as old as 10-15 years old). However, this summer when I started it, the pump will not operate.  The sprinklers operate and water flows out at the low system (municipal) pressure.

Any insight what the problem may be and what troubleshooting you recommend?

Answer
Hey Shawn, start with the controller, in the back of the unit you will notice a terminal strip. You need to check your voltage with a volt/ohm meter. touch the negative lead to the C(common) terminal, and the positive lead to the PS(pump start) or MV (master valve) terminal, whichever one the wire is hooked up to. When you turn on a station, you should get between 24 to 26 volts. If the reading is bad and you are not getting the proper voltage, then the controller might be defective. If the reading is good, then you need to check the voltage at the relay switch. If you are getting the proper voltage at the relay switch, the the relay switch might be defective. If the voltage is good at the controller, but not good at the relay, then it is probably the wire. Check your wire for cuts or breaks. So to re-cap, it could be the controller, the relay switch, or the wire. It could also be the pump itself, if you determine the controller, the relay switch, and the wire are alll working properly. Good luck and have a great day.