If you aren't using color-coded cable(s) to connect the valves, then you could easily mess it all up.
`
To make an extreme example, imagine all the wires are the same color. You would have to mark the ends of every wire currently connected to the controller's outputs with a numbered tag. Then you would take resistance measurements from each wire to every other wire, one at a time, and write down the measured resistance value on a grid chart. That can be a lot of measurements (45 measurements for 10 wires) - but it will pinpoint which of the unknown wires is the common. Once you are certain of the common, you can work out the rest.