2019 kw w9 no crank no start

By "cross solenoid" you mean bypass it to the starter? In this case it's just a bad solenoid which is actually kind of a common problem in these things. Not hard to replace at all. That "buzz" from the fuse box is probably a warning buzzer that you're low on battery. Also, check your ground. My diesel tractor did the same thing to me the other day, and after monkeying around with it, my brother discovered it was just a bad ground. Cleaned it up and it started like a champ. But it was doing the same thing that you were saying yours does. Hope this helps!

 

Maybe both the solenoid and the ignition are bad. But I would really check you ground first. When my diesel tractor was doing the same thing, I initially thought it was the ignition. Everywhere I tested it pointed back to the ignition. But then me genius brother found it was just s bad ground. Cleaned and started right up. What I would do also is take the solenoid and ignition out and have them tested. Have them tested at Napa if you can. Let me know how it goes, hopefully that should fix it.