Serial # 0160063016 Model # G10-55-A Turb Stopped going forward and reverse. Dash Displays - Canbus Fault Signal Invalid I noticed that the rpm and hours will go out and then periodically come back on. The oil gauge fluctuates. The temperature gauge never moves off cold. And the red light above it is always on. All fuses including the ones in the dash have been checked.
Probably corrosion in a wire connector somewhere.
On these guys can bus failure failure can be misleading. Easy way is to think of is one or more component is not communicating with another. You lost forward and reverse. I would first check your battery ground and chassis grounds. That would be first second would be my F&R switch third would be forward and reverse coils. I would suspect F&R switch over coils since its the only common link if you lost both at once. But since you have other issues with rpms not responding i would lean more towards a bad ground or as skata said corrosion or bad connection. Can bus issues can be hard to pinpoint since it does not directly give you a code or a starting point. You really have to start with the simplest solution and your way forward. Had a few bad harness that had rubbed through on the frame but 9 out of 10 times its a bad ground or connection causing a can bus failure to pop up. Sorry could not give you a more direct answer but this is one of the harder issues to trouble shoot.