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

New to the site. There's alot of sprinkler knowledge being thrown around here and I am a good listener who loves to learn.
Learned alot on my own but I still have a question or two.

I have a 7 zone system with a Hunter Xcore controller. Everything works fine except Zone 4 decided to stop working. Through researching the internet on how to troubleshoot this problem, I've narrowed it down to having a "nicked" or almost cut field wire to the zone 4 solenoid. With the zone not running, I get the same voltage reading as the controller puts out to that zone. But when the controller kicks in for that zone, the voltage reading goes down to 6-7 volts. Solenoid won't open. Correct me if i'm wrong.

Here's one of my questions.
Would one of those Valve and wire locators being able to find the damaged wire so I don't have to dig a trench and lay new wire? I know where all my valves are. They are scattered in various places. I just don't know if zone 4 wire follows the route of the valves. They seem to laid out in a line all the way around the house and end up in the front yard, with Zone 4 being the last one. Which leads to my next question......

The wires coming out of my controller are color coded. 10 wire cable. It travels down the pvc pipe, through the wall, then down into the ground. At all the valves, there is only red and white wires. Question is...
Where is the splice from the colored wires to the red/white wires? There's no box that I can tell. May be just a bad connection at that splice. But where is it? And why would anyone install a sprinkler system like this? Why not run the entire distance with the cable you started with out of the controller? I know it's to save money but....jeez.

Sorry to be long winded, but I like detail.

Ok. Let me clarify.

When I check the voltage, with the solenoid disconnected, at the valve, controller on, I get the same voltage reading as the controller puts out to that zone.

When I hook the solenoid back up, and energize the solenoid, is when it drops. In other words, put a load on it.

Went ahead and replaced solenoid and diaphragm to rule those out. Sprinkler parts are cheap. Now I have spares. LOL.
I've also tried the swap to a working zone next to it and zone 4 runs great. This was after I ruled out the common. Cause I thought I might get lucky and just have to jump the common over from that nearby working zone. So that tells me it is the field wire, directly from the controller.

Nope.
Not gonna spend a lot of money on this. In the meantime, I will just go out in the front yard, reach down in the valve hole, turn it on manually. Then go in the house, and tell Alexa to give me a "XX" minute timer.

For all the time, cost, and labor involved in solving issues like this, seems like the installers would insist on doing it right the first time and lay the right cable "all the way" so there would be "spares". At least, that's how I would do it. Provides an easy fix down the road if issues arise. Just swap a wire at the controller and swap a wire at the solenoid.


TA-DAAA!!!!

Appreciate everyone's input. Thanks