How many valves do you have? If you have a six station controller and six values then the black wire may be used for one of the valves. The white one most likely is the common, and the five color wire plus the black wire are for the six valves.
All the valves need to be connected to the common wire (white?). Verify that the white wire is connected to the common post on the controller and match one of the color wires connected to the controller to the desired valve.
This post has been edited 3 times, last edit by "worachj" (Jun 5th 2011, 10:26am)