Auto A/C question

GKC

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We have a 2003 Ford Expedition Eddie Bauer 4 x 4 Texas Tow Edition. We bought it new, and it now has 160K miles. It looks and runs like brand new. It has every option on that was available that year, and one that we haven't found on a new model: it's paid for. We've never had a problem with it, and haven't had to do anything other than routine maintenance (oil change, tuneup, battery, tires, etc.) We've never had a car that has been this good, and in the past we'd trade cars very often. This one has made us want to stay with it.

We are having a strange problem now with our A/C. Fortunately, it's the time of year when it's not such an issue. I've got a recommendation for a good local mechanic, but with the holidays he's really backed up, so it'll be a couple of weeks before he can get me in.

What it's doing is this: the A/C come on and cools as normal, while idling or in reverse, but when I put the truck in drive and accelerate, the air starts blowing through the defroster vents. When I let off the accelerator or put on the brake, either way, it again blows through the vents directed at the driver and passenger. The rear air acts normally. I've tried taking it off the thermostat, and using the various vent settings, and it doesn't make any difference.

I'm thinking it must be some kind of valve or switch, but all my A/C expertise could fit in a thimble. It still blows ice cold air, and in all other respects works like it should...and it's not like I'm really going to need it for the next few months. I do want to get it fixed, before it gets worse or goes out completely. The heater does work correctly.

Any ideas? I'm mainly just curious, since I am going to take it to the mechanic as soon as I can.
 
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Look under the hood and check the vacuum lines that you will find around the drier. The larger cylinder that sweats when running the AC.

Vacuum controls the opening and closing of the vents. There are also vacuum lines behind the switch on the dash.

It's an easy fix and I usually find the broken or cracked line on the right exactly as described in my first sentence.

Good luck.

Bruce
 
Auto A/C Problem

Ken,

My vote is also for a broken, cracked, or leaking vacuum line. It could also be the central vacuum control valve. It's almost fifteen years old by model year and about time for these problems to crop up. Unless it's located in the firewall in a hard to check area of the system to easily access, the damaged hoses can often be identified visually and quickly. It's also an inexpensive repair if it's a vacuum hose.

Bill
 
Thanks all! I appreciate the replies. I hope it's something that simple.

I'll update this thread when I get it fixed.
 
My Father assured me that we don't need AC in Oregon, at least that's what I remember.
 
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My '95 F-150 had the same common problem as you are having.

Mine had a white plastic tube that was located at the top of the firewall on the passenger side. A black rubber vacuum hose slid over this white tube. The white tube had disintegrated and allowed a vacuum leak.

That leak made the defroster door malfunction when you tried to use the Max setting on the AC.

It's been a few years ago, but I remember replacing that white tube with a black rubber standard vacuum line. That solved the problem.
 
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Just a thought, Newer cars have electronic actuators.

I'm not gonna tell you more about you're particular vehicle because I don't know. Look it up.
 
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Ken,

I ran a Search using Google. Looks like this is a relatively common problem with your make and model truck. In some cases the vacuum lines were routed too close to the battery and with the passage of time battery acid caused the problem:

03 Expy - No A/C coming out of front vents - Page 2 - Ford Truck Enthusiasts Forums

Pictures of the repairs and damaged vacuum lines are included in a few of the responses.

Bill
 
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Hello, I vote for a vacuum leak, an old trick good mechanics use is using a vacuum line to put refrigerant gas at a low pressure in the system and use there refrigerant leak detector to find the vacuum leak! Ben there done that!
SEMPER PARATUS
 
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That is Ford's way of telling you that there is a vacuum leak. I have the exact same vehicle. 2003 Eddie Bauer. A couple of months ago, the AC and heater started blowing only through the defroster vents. I plugged in an OBD II scanner and it told me I had a vacuum leak.

Sure enough, I found a cracked vacuum hose, replaced it, and viola, AC works again. Look under the hood, passenger side, next to the fire wall. I had to pull the battery to get to it and replace the bad hose.
 
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