SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

I am adding to my yard and will need multiple new stations. I would rather not have to run a new control harness across the existing yard, lots of reasons that make it quite difficult. It seems to me that with a second timer (station controller) I should be able to use the wiring harness I have already at the central location of my control valves (across the yard and near where I want to run my new lines from). Would I be able to run a separate ground wire from the new controller and then tie into the existing wires at the end of the harness to use those wires for the new valves. While the existing wires would be wired to one side of two different valves it seems only the one with the ground wire to the appropriate controller would actuate. Has anyone done this type of wiring or heard of it? Basically using one wiring harness to actuate two sets of valves from with two different controllers? WOW ... sorry so long and rambling, hopefully you get the gist. Thanks for any input!