2015 T880 Blend door actuator

Working on a 2015 T880 that has a manufactures date of Dec. 2014. The cab heater is not working but the fan is blowing. Found Blend Door Actuator was bad, it had a stripped gear inside. Bought new actuator and tested before installing. The actuator only turns counter clockwise as you are looking at the end of the shaft. This would make the blend door go to the A/C side and block the heat. It will not turn the opposite direction. Is it the HVAC controller with the 3 knobs on the dash that tells the actuator which way to turn. The actuator only has two wires so the polarity must be reversed to make it turn the opposite direction. Trying to decide if it's the controller that needs replacement. Thanks

 

Programming has been discussed and I will make that call tomorrow and find out if that could be it. I would have thought that they would have said something when we purchased the actuator from Kenworth!

 

Thanks for your reply

Thanks for your input, its appreciated!