2016 Pete no defroster

Same as the other thread it’s your gate actuator think I just bought one and Peterbilt put it in my 379 it was like $80 maybe took me about 15 minutes to put it in.

 

No you can do that yourself not a big deal it’s behind the Dash on the right side of the steering wheel in a 379 anyway!

 

Pop the dash panels off. Follow the "Y" that does the defrost piping down to a round drum. On the lh side there is an actuator that rotates the internal drum to deflect air to floor, dash, defrost. Pull the actuator off and see if you can rotate the drum by hand. If you can, replace the actuator and continue. If you cant, need to either blow air down the defrost vents or bore scope it to see whats jamming the drum. Sunflower seeds, glass chunks and pens are common. Worst case it snapped the actuator drive off then you gotta split the module and replace the internal drum deflector.