Ok, have a question that I have been struggling with. I’m having trouble with the heater control(defrost, floor, vent) not switching completely when the top **** is turned. There is plenty of air coming out of the floor vents and when I switch it to defrost, it makes somewhat of a change but doesn’t fully switch functions. It’s not a cool/warm issue or a blower intensity issue. Is there actuator I’m not aware of. The blend door moves when you turn the top **** but doesn’t fully switch the functions ?? Anyone got anything. ??

 

Even when set on Floor heat, there will still be some airflow thru the defrosters, same goes for the defrosters, you will still get a bit of airflow thru the floor vents. So long as the strongest flow is going where you think it should, it's working right. If you are not getting what you think is adequate airflow where you want it, need to check for vacuum leaks. Vents are all controlled by vacuum. The blend door just determines temperature, and is controlled by a cable from the temp ****.

 

First of all thanks,
Well, there isn’t really a strong set airflow. When I turn the fan switch on say, defrost I get a little flow to the defrost vent but, the bulk air still goes to the floor. It’s weird. Pretty much any setting I put it on the bulk of the air defaults to the floor ??

 

Check the **** .Wear and tear of use makes the clip weak that holds and controls what you select,LMCTRUCKcom have them in stock.....Just a thought................

 

Check all the lines and such as well. If there is no vacuum, vents should default to the defrosters...... If there is inadequate vacuum, all sorts of strange things can happen. Checking the control head first sounds like a good idea.

 

Yeah, already replaced the whole dash control cluster ��

 

Then make sure you have good vacuum to the controls.