I tried to install a rain sensor (Hunter WRC) on a Rain Bird RC-7C controller this morning. Here is the problem. There is a jumper between the 24v terminal and the common terminal. When this is removed, with or without the sensor installed, the system will not operate. Is this jumper normal for this controller (I only have 1 other RC in my customer base and never noticed it). I have the following hooked up for the rain sensor: yellow (2) - 24v white - Common blue - common out to valves orange - not used Any suggestions are greatly appreciated.