Hi there, I just installed something called "Add a Zone". It does exactly what you described. It's used when you don't have enough wires to run all your valves. Sometimes running a new wire is nearly impossibe or very costly. I've been in the irrigation repair buisness for 9 years and done thousands of jobs. I've always avoided installing this device because of the cost factor. It was over 100 dollars. But let me tell you. I was very happy with the results. I have no problem recommending it. Your local hardware store probably wont carry this. Try the following link:
http://www.sprinklerwarehouse.com/detail.aspx?ID=1781
If I can't fix it, it's broken!
