Hi everybody, i'm fairly new to the forums but it seems like you are all pretty well educated about your trucks. I have a wedgewood blue 2004 F150 supercrew (new body style) with the 5.4 and my issue is with my heat/ac controls. No matter if the heat or a/c is on, it only blows air through the dash vents. If i switch the ***** on the panel to the floor or defroster, the air wont switch away from the vents. I do not have the digital climate control, just the manual one. any ideas if it is the panel itself or something else?????

 

My truck isn't as new as yours, but the system has been the same for years so it might work the same as mine still. The vent control switch uses engine vacuum to change where the air comes from. When there is no vacuum present the controls default to defrost so you can still defrost your windshield to see. There will be a vacuum hose that passes through the firewall which goes to the vent system. The hose is probably plastic where it passes through the firewall. Follow it back to the engine and make sure it's still hooked up. Make sure the plastic isn't broken.

Did you do something inside recently, like put in a new radio? The vacuum may have been knocked off the control switch.

 

havent done anything inside since i got the truck, and i would love it if it would at least default back to defrost. then i might be able to see out the windshield in the morning. i'm suspecting a vacuum leak, but i certainly dont hear one....

 

Maybe the switch broke. You can unhook the vacuum line from under the hood and see if it will default back to defrost. If you leave it that way you will have to cap off the vacuum port on the engine. I'm sure someone with experience on these newer trucks will jump in eventually and give you an opinion.

 

Understand your issue with blowing out of dash only, seems like we are not switching fully. Inside cab, look at plenum chamber you will see an actuator, vaccuum line and connecting to a lever. The lever is the blend door and directs the air as selected. Watch this lever as you select the air flow. Vaccuum one way and spring loaded the other. Manually move the blend door, does the air flow switch? Have been more concerns with the vaccuum line going through the firewall forward of glove box than issues with blend door. Put the seats all the way back for better access to the plenum chamber/blend door inspection.

 

thanks for the info, i'll give it a look this weekend.