07 PETE 379 NO AIR THROUGH DASH VENTS

If I'm not mistaken I think you can go under the dash on the passenger side an get to it. Something is either blocking the flapper or the cable has come loose or is broken. I've had that problem in the past but it's been so long it's hard to remember exactly how I fixed it.

 

Take the glove box out, there's is an actuator (turns the door) either it's bad or its catching on something

 

On my 386 if you take the panel off in front of the passenger seat all the HVAC crap is under there. There are 3 actuators that control the blend doors. I would guess one of them was bad. Very easy to do it yourself and very easy to figure out. Take the panel off and fiddle with the A/C heat controls and the one that aint moving is the bad one. Anyway that's how I figured mine out.

 

The 2 on the passenger side are easy. The one closest to the door is the fresh air and the one left of it is the blend door. The mode actuator controls the vent, defrost and floor vents and is in front of your right knee on the end of the air trunk. Take the lower dash pieces in front of drivers seat, and steering column cover off, remove the vent piece that runs across and you can see it up there. the 3 screws hold it on and face left are 1/4 inch. Its not a fun job but if you dont mind laying on your back on the floor with your feet in the sleeper it can be done on an hour or so.

 

Have a 92 379. Defrost and floor blows good. Only the passenger side dash works. Not the drivers. Any ideas?

 

there is easy to get to air ducts if you take the dash panels off. maybe one popped off. take a look

 

I can get to all of them and even move the flappers. Unless a flapper is broke off inside. I’ll do some more looking. Thanks

 

I wonder if its the same for a 2014 Peterbilt 579 MX13.
I changed 2 actuators on the passenger side. I wonder if there is a 3rd on the drivers side?
My problem is my air is NOT blowing thru my front vents....only out the side ones facing the windows