I have a 2005 Yamaha Kodiak 450. It will go into 4 wheel drive . You can hear the servo motor engage and you can tell that is is enaged by the display, and on the trail. When you try to engage the diff lock the display blinks and when you give it any throttle the rev limitter activates. The servo does not try to engage. I have checked and swapped the relays under the seat. I cannot see any visable wiring problems. I bought a shop manuual, but it is not a very good trouble shooting guide for this problem. Has anyone had this problem on a kodiak, grizzly or rino. Any help would be appreciated.