The zero comes when 2 or more of the things monitored are not working correctly-up to speed. Shut all off the turn on the rotor switch turn the knob untill the buzzer quits, then do the same with the fan speed, if buzzer quits there ok, leave rotor and fan off, turn others on one at a time should have one number come on and stay that would be a problem one etc.
If you have the problem right away before you even get this far, probably a wiring problem most likely in the cab
If you have the problem right away before you even get this far, probably a wiring problem most likely in the cab
