Well, I think I did a boo-boo during my attempted fix. I tried the extra wire on zone 6. So, I unhooked valve 6. The extra wire was connected to the common, so I unhooked that, and connected to zone 6. Unfortunately, I connected the old zone 6 wire to the common also -- like the extra wire had been. I hooked the unused wire up to 6 at the controller. I ran thru stations 1-4 and worked as intended. When zone 5 came on, nothing happened. I had 0v at the terminal. Same with 6, same with 7 when I went there. Then went back to 1-4 and now had 0v on all of them too. So, if the theory was 5&6 live wires were exposed to each other, could I have cooked the controller when zone 5 was activated -- the controller was trying to drive 5, while the old 6 wire was connected to common, and we think 5&old6 are shorted somewhere??? The fuse is good -- I'm getting 28v across that. I subsequently unhooked the old 6 from the common, but still get 0v on all stations.
I suppose I could try a new controller and take it back