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chris, Ford Mechanic
Category: Ford
Satisfied Customers: 3521
Experience:  ASE Master -Ford senior master-20 years experience
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cab air flow..defrost does not blow much air on the windshield

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what operates the air control for defrost and other settings for cab air flow from the fan? Is it vacuume or mechanical?My heater when set on defrost does not blow much air on the windshield even with the fan on high(4). T

hi there


Need some info ,,, what year F150 do you have ??


also do you have poor air flow in all setting ,, floor, panel, defrost ,, or is just in one mode



we can go back and forth on this page



Customer: replied 6 years ago.

My truck is a 2007 ford f150 4x4 with 5.4 engine

I get good air flow on the feet/chest or just chest settings but not the other settings

ok,, on a 2007 F150 the doors in the plenum chamber to control air flow are controlled by three electric motors ,, there is no vacuum used


if there is a problem with the system and you have ATC,, push buttons to control your a/c ,,not three knobs like manual a/c ,, then there is a self test you can do on the system


so do you have ATC ,, buttons you push to control the a/c and heat ,, if so , I will tell you how to do the self test ..



Customer: replied 6 years ago.

There is a push button to activate the air conditioning and then three knobs to set fan speed/temp setting/air flow control

ok, so there is no ATC and you can not do a self test ..


I guess you can take a look at the main air direction motors on the left side of the dash , grab a flash light and get on your back in front of the drivers seat and look toward the center of the dash , up high ,, there you will see a electric motor , its called the mode door motor ,, as you look at the motor , operate the functions of the a/c from floor to panel to defrost and see if the motor is moving or anything is loose





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