I have a customer that is having problem with a rainbird shallow well pump irrigation system. I went to check it out and the controller (Rain Bird ISA 406) is opening the valve solenoids but the pump will not kick on to supply water to the system. There is a fuse in the Rain Bird Controller that keeps blowing as soon as you turn on the system. I am thinking that the Pump Relay has gone bad. I just looked in the manual for this system online at http://www.rainbird.com/pdf/diy/man_ISAseries.pdf and it lists several possible issues: 1, Bad Pump relay. 2. Short in the wiring to a valve solenoid. 3. Short in the electrical timer. Not seeing the system, what do you gauys think the most common problems are with this from what you have seen in the field? The customer has a extra, Brand New Pump Relay box that was left when they bought the house. I am thinking that this has happened more than once with the previous owners of the house and they kept a spare relay on hand. Any thoughts?