Figured it out... in another valve box there are a bunch of splices for zones 6-8 and the master. There was a loose connection there with the common.
Latest update.. On the panel, if I use the ohm meter setting and touch common and a zone, zones 1-5 get about 26 ohms, and zones 6-8 and master get a "1" (probably same as infinity). I dug up the box for zones 6-8 (it is buried under sod, *sigh*) and did some testing there as well. I took off the wire nuts for all of the connections. I touched the ohm meter from the common (they were still all connected) to each of the other wires and got about 26 ohms. But no voltage was to be read, even though...
