Help with a/c
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Joined: Jun 2009
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Help with a/c
I have a 2003 Ford F150 Lariat 4x4. The a/c in the truck has the auto feature whatever that is. My problem is, the only setting I can get cold air to blow out of the main vents is PNL FLR. If I cut it on auto, or Max AC it blows out of the dash vents like it's on defrost. This is very aggravating. Can anyone suggest a quick fix or am I in for major surgery to fix this? Thanks very much.
Hotshot
Joined: Jan 2004
Posts: 19,763
Likes: 1,081
From: St Louis
Either one of the vacuum motors has failed or, more likely, the EATC control unit has failed.
Possibly there is a small vacuum leak in the supply to the system that is preventing it from being able to fully activate the vacuum motors. If this is the case, then you'd usually notice airflow diverting to the defroster outlets, especially under heavy acceleration.
Possibly there is a small vacuum leak in the supply to the system that is preventing it from being able to fully activate the vacuum motors. If this is the case, then you'd usually notice airflow diverting to the defroster outlets, especially under heavy acceleration.
Fleet Mechanic
Joined: Feb 2006
Posts: 1,776
Likes: 5
From: Lorain County, Ohio
Either one of the vacuum motors has failed or, more likely, the EATC control unit has failed.
Possibly there is a small vacuum leak in the supply to the system that is preventing it from being able to fully activate the vacuum motors. If this is the case, then you'd usually notice airflow diverting to the defroster outlets, especially under heavy acceleration.
Possibly there is a small vacuum leak in the supply to the system that is preventing it from being able to fully activate the vacuum motors. If this is the case, then you'd usually notice airflow diverting to the defroster outlets, especially under heavy acceleration.
Since you can get it to work correctly on PNL FLR, I also suspect the EATC unit.
More Turbo
Joined: Aug 2006
Posts: 530
Likes: 2
From: W. Wisc
Could also be a bad vacuum actuator. These are the little silver cans under the dash that pull the air direction doors around from one position to another by the action of vacuum on a diaphragm inside it. Often hard to get to but easy to test. I haven't looked into them in this vehicle yet, but had a bad one in a previous Ford.
-Dave
-Dave
