Well, after 3 hours on my belly and knees, the sprinkler system that we "broke" is finally fixed. We had to cut a section of wire out of it because since it was installed, the tree root had grown around it. But of course, I didn't have any "proper" wire, since one was a 5 wire strand and the other was a 7 wire strand. But I did have a spool of CAT-5 cable which is 8 strand, so I used that to splice it, and put it inside a PVC pipe so it would be a little more out of the weather. Now, the only problem is one of the stations remains on the whole time, whereas the others move correctly. The previous owner said that the controller was damaged when a tree was cut down, so I suppose I will need to dig that up as soon as I can find it and replace it.
But, for now, at least we can manually turn on the stations and keep the lawn watered.