Heater fault codes

Hi everyone, I have the following codes showing in conjunction with the heater not blowing warm air. 

B1262 Defrost servo motor circuit failure

B1263 Vent servo motor circuit fault

B1239 Air flow blend door actuator circuit fault 

I’m familiar with a lot of threads about blend door actuators/stepper motors etc and I can see the actuators without pulling all the dash board out. Yes maybe there’s a tooth broken or an actuator has failed or a blend door is stuck. Before I hang upside down with the back of head resting on the brake pedal swearing profusely …..

What I’d like to know, if anyone has experience of these codes together, is, Is it certain that there’s a mechanical failure or could it be simply a broken or frayed wire somewhere ? If so how can I identify where ?

Has a mechanical failure led to these circuit faults or is perhaps one circuit fault that explains the three codes ?

Thanks for reading

Paul