Question
I have a rainbird esp controller that has worked fine since
installation a year ago.  I have 6 zones, and recently I
discovered a large water puddle underneath them.  I dug up
the area around the valves, found a leaking joint, replaced
the pvc, and all seemed fine.  I can use the quarter-turn
handle on top of the valves, and all 6 zones work without
any leaks.

However, now the controller does not work on any valve.  I
have tried manual and programs.  I have checked the
seasonal setting, reset the system, and cleared all
programing.  Still nothing.  The wires around the valves
don't look damaged, I will have to start peeling back tape
to see if I got one with the shovel.  

How can I test the electrical system to look for a problem?  
I have considered placing a ammeter on the connections at
the controller, and then again at the valves and test the
functions, but I really don't know where to start.

THANKS!!!!

Answer
John,

The electrical system for irrigation is rather simple. One wire from each valve is connected to the "COM" wire. Then each valve gets it's own individual wire from the controller.
To test: turn on a zone, then touch one lead to the "COM" terminal and the other to the zone terminal. You should read 23-27 volts. To test at the valve you need to connect one lead to the "common wire" usually white. Then the other test lead goes on the other valve wire.
I think your following the correct path. You probably knocked one of the wire loose while digging. Since all zones aren't working it will be a "Common" wire that is broken. (just because the wire nut is on doesn't mean the connection is still good)
Good luck.

Matt