Hey everyone. I have a 2002 379 and the heater only blows out hot air. the control doesn't adjust it. I took the control out of the dash hoping it was just a mechanical arm that opens and closes the mixing gate. Nope, this sucker is electric. It shouldn't be too hard to troubleshoot but I don't know where to look for the solenoid and mixing gate. Does anyone know where this is. Any tips would be appreciated. Thanks.
It has an actuator that operates off that controller that in turn opens and closes the gate you're talking about. It's under the dash on the passenger side where the filter is. Remove the dash panel and the plate behind it and you will see the temp actuator and one that controls where the air goes like defrost or vent etc. and for heat or AC. Hope I explained it right. Edit: They are labeled so you know which one is which. Pretty straightforward and simple setup on these. I have an '03 379EXHD and just recently poked around and cleaned the filters and condensers etc. to improve airflow and get my AC blowing a little colder in preparation for the upcoming summer heat. I like to be prepared ahead of time.
You also have the same setup under the bunk for the sleeper. The Bunk on/off switch in the dash must be on for the controller in the sleeper to work.
Cool! that's all I needed to know. Thank you. Mine is a day cab so I won't need to worry about the other one. It will be nice to get it fixed so I don't need to drive around with the windows open.
