Right, I've seen this pulsing. It did it on every station. I changed the faceplate with one I carry for testing purposes and it cured the problem. I highly recommend you get rid or repair your current controller. It'll damage the system.
www.sprinklerwarehouse.com/v/vspfiles/search/search2.asp?Extensive_Search2=N&keywords=rd12
This post has been edited 3 times, last edit by "mrfixit" (Aug 15th 2010, 4:14pm)