Hello,
I’m making this post to help someone who has the same issue.
So, i have end of 2021 cf 625.
I’ve owned it for about a year. The mileage is currently 800 km. A few weeks ago, the first snow came, and I went out to do some "drifting" in the snow.
At the end of the day, the machine overheated. I let it cool down and discovered that the fan fuse had blown. I replaced the fuse and kept riding.
That evening, when I got home, the machine died—it turned out that the main fuse had burned out. On top of that, I noticed that the 4WD wasn’t engaging.
I took apart the differential and discovered that the motor was burnt out. I bought a new servo motor, installed it, and tested it. It worked fine. I rode about 10 km, and when I engaged 4x4 again, I discovered that the motor had stopped working. I removed the motor again, and it was burnt out once more!
I returned the motor to the store and luckily got a new one for free. However, I realized the issue wasn’t with the motor itself but elsewhere.
I called every repair shop I could find to ask if they had encountered this problem before. No one had any answers, and they all said they were hearing about this issue for the first time.
I started troubleshooting the issue and replaced all the relays. Eventually, I discovered that water or moisture had gotten into the switch. Additionally, the circuit board was damaged, likely due to water or moisture as well. So at the end of the day the problem was switch.
If you want to replace the servo motor, you need to detach the differential from the body. Otherwise, you won’t be able to remove the servo motor bolts. This takes about 30 minutes.
Replacing the switch is quite tricky if you don’t want to remove the plastic body panels. It’s doable, but you’ll have to work in pretty tight conditions.
Switch cost about 130€
Servo motor cost about 160€ - if you wanna do it really cheap you can order the motor from china (just small motor not entire servo motor what they will sell you at the shop) will cost you about 10€
Some pictures here: