We have a 2018 with literally only 115 miles on it. Turned the key to fire it up, and the dash screen lit up as normal.... I Hit the starter and the engine turned a half of turn and then completely died out. All the electrical is completely dead now. The only way I can get the dash screen to light up is to disconnect either battery terminal and touch it back on... then you can see the dash computer cycle through as denoted in the attached video. Once the cycle / reset is complete, nothing happens.

The Battery is 100% charged and I replaced the starter relay in hopes that would solve.... But still nothing. I have 12.7 Volts to the key ignition switch, and also I have good continuity in the switch so I know it's good. If I pull the fuse cap/4 wire plug fitting out of the starter relay, as soon as I reattach it, the dash lights up and cycles through again. I've checked all the fuses and relays... the fan fuse is blown, and as soon as I replace it and turn the key switch, it immediately blows again. The only thing that occurs when I turn the switch (with the blown fan fuse installed)  is a "click" in the metal electrical panel just above the power steering.... Not exactly sure what this panel is (maybe the ecu?) but I have confirmed 12.6v power going into it and 0 coming out at the bottom (where the power steering main power plugs into)

At this point, I have around 5-6 hours in just tear Down, testing and diagnosing... so I bit the bullet and took it to the dealership (just don't have the time to spend trying to resolve). My guess is that it's probably a bad ground connection somewhere or crossed / burned up wire. Will keep this updated as I can hopefully help out anyone else who may run into this issue.

My first thought was a loose/high-resistance connection someplace, and a bad ground would be my first guess.

And a short someplace is blowing the fan fuse.

Wondering if a critter got in there and chewed some wires.

Well... got a call back from the dealership. They disconnected all the Auxiliary powered components, and narrowed it down to a defective / broken ground somewhere within in the wiring harness. He said that directly under the fuse box is the main ground which contains a black and white wire.... Somewhere inside the wiring harness, there is a ground short, and it would take hours and hours trying to segregate and narrow it down to where.

The dealership called CF Moto for assistance and to see if it would be covered under "Good will assistance" and of course it's not. CF Moto recommended a complete replacement of the wiring harness.... Total cost $975.00!!! Unbelievable for  quad with only 100 miles and less then 10 hours on it! I called CF Moto directly and of course, they won't do shit since it's out of warranty.

The tech made a point to mention that This problem does happen and CF Moto is aware of it, but won't do anything about it. At this point, not sure what to do. Maybe just buy a new harness and try to install myself... or just sell it as is and try to move onto a reputable quad like Yamaha, Honda, Or Polaris.

Regardless,  CF Motos are the biggest pieces of shit. Having a Yamaha for over 20 years, I've never had an issue like this. I'll never buy another CF Moto again.

I rather doubt Yamaha would warranty an electrical issue on a 3 year old machine with 100 miles on it either.

Any signs of animal involvement?

If this "does happen", then they (dealer/CFMoto) should know roughly where it happens. Hours and hours to track down a broken ground or short to ground sounds excessive (unless they are including time tearing the machine down to gain access to the harness).  It's likely a simple fix once located.

A new harness would be excessive unless there was significant damage to the original harness. $900 buys a lot of labor.

Sorry this wasn't more helpful.

Well I bit the bullet and ordered a brand new wiring harness and service manual. After Taxes, and Shipping, total cost was around $450.00. Yesterday I took on the tedious task of replacing the entire wiring harness, and quite frankly, it really wasn't that bad. After removing the fuel tank; and While starting at the tail end and working extremely methodically towards the front and swapping each individual connection one by one, I was able to do a complete swap out in about 2 Hours (Plastics were already removed). The hardest part was when I got the the main relay box... its very tight to swap out all 7-8 relay holders

Once everything was was rewired and connected, I reinstalled the fuel tank, and turned the key for the moment of truth......... It Fired right up!!!! Thank god. And so far, everything runs perfect. Took me about another 1/2-1 hour to reinstall the plastics and racks, but I'm beyond happy shes running again. Still, super pissed off at CF Moto that this issue even occurred in the first place, but glad to finally have it back up and running. I sure hope no one else has to deal with this issue!

[2015 Z Force 800 53/Trail EPS]

Wow..congrats! glad it paid-off.

Did you find the source of the problem in the old harness? Worn wires, breaks, melted connectors, that sort of thing.

Wouldn't it be a great thing if the manufacturer would include one or two spare wires when building these harnesses? That is standard practice in the electrical industry and large bundles they might add 5-10% spares. It would probably add a buck to their cost for a couple spares, so cost savings always wins out.

Congrats on replacing the harness yourself. Well done, Stan