Question
"I have a RainBird 24-volt ISM-9 Time/Controller and I want to know
what I need to run it and how to hook it up. (25.5 vac in and 25.5 Vac out
to valves) I am a retired pipefitter, installed regular irrigation
systems, but never a solar system.  Thanks!"  

Answer
I'm afraid that I'm not very familiar with that timer. All timers are basically the same. You have a common wire (usually white) that connects to your common terminal on the controller and then to the valve. You also have a zone or valve wire that connects to the valve as well. The common connects to all the valves and the zone wire connects to only one valve. Try going here for more info. Hope I helped. http://www.rainbird.com/DIY/literature/timers.htm