Another weird AC problem

  #1  
Old 05-26-2010, 11:40 PM
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Another weird AC problem

Hi Guys,

First of you are all a great big help with my AC lately and I cant thank you all enough.

I have a 2003 Lincoln Navigator

I run my air on auto on 60 degrees on the climate control and it is very cold. Everything is fine until I have to get up to speed andf gun it, where as the AC doesnt come out the front vents anymore it goes to the defrosters and is still cold. Then, and this is the weird part, once up to speed and the truck gets to cruising and the tach drops, the AC starts to come out of the front vents again.

Could it be a vacuum problem, with the engine taking all the vacuum when getting up to spped, then once up to speed the vacuum is strong again and the vent goes back to working normal? Im confused! LOL

Anyone have any ideas?

Thanks
Brian
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  #2  
Old 05-27-2010, 07:49 AM
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Go back and read the FAQs yet again...
 
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Old 05-27-2010, 10:52 AM
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I did read the FAQ there was a very general answer that says that it is the blend door.

I have the question why would an engine under acceleration make the blend door actuator which is an electrical item, not work properly?

Or is there a vacuum system that also is an assist on the door?

Also my air and heat work in all modes something was said about the heat and max ac only working. So why does others only max ac and heat work but with mine every mode still works?

Thanks
Brian

P.S how do I get my vehicle specs in a signature? I looked everywhere in my profile and account and couldnt find anything to do the sig.
 
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Old 05-27-2010, 10:14 PM
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The vent selector door is vacuum acuated. You have a vacuum leak. On the SDs the leak is usually in the auto locking 4x4 hub system somewhere. Not sure on the Navigator.

User CP> Edit signature. It's in the options on the left side.

-Dave
 
  #5  
Old 05-28-2010, 06:45 AM
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I did read the FAQ there was a very general answer that says that it is the blend door.
No, you did not read that. Here is what is written:

Problem: Air flow has defaulted to the defrost vents (either all the time or under acceleration).
Solution: The system is designed to default to the defroster in the event airflow control is lost. Intake manifold vacuum is supplied to the control head, whether manual or automatic (electronic) to operate the vacuum motors.. A very common failure is a split, cracked, or otherwise leaking vacuum line located between the battery and firewall. Other causes include a leaking vacuum reservoir (inside the right front fender), faulty check-valve inside the dash, or other vacuum leak in the system.
Can't get much plainer than that without charging a flat rate fee.

Also my air and heat work in all modes something was said about the heat and max ac only working. So why does others only max ac and heat work but with mine every mode still works?
Problem: The A/C compressor runs in different climate control positions.
A:Generally, it’s supposed to be enabled in all settings except OFF, FLOOR, and VENT. Refer to your owner’s manual.
Let's work on that "reading comprehension" thing.
 
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Old 06-06-2010, 04:34 PM
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Ok I figured it out and it was a vacuum leak, I had knocked off a vacuum line from the pass. side of the motor it looks to be a vacuum line that goes to a valve that is on the lines that go to the heater core. I put the line back on and it now is fixed.

Thanks to both of you for pointing me in the right direction. Sometimes reading FAQ's and then hearing other opinions help alot to get my mind to thinking. LOL

Thanks again
 
  #7  
Old 06-10-2010, 08:44 PM
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Vacuum Repair at Firewall

Yes, like the previous members, I am in debt to the expertise and knowledge provided in this forum (fixed a rear blend door and isolated a vacuum leak for door switching). {{Thank you!!}}

My issue is with my ongoing vacuum repair. When attempting to replace a damaged line, (I thought) my handling of the fragile line broke it off at the firewall. Two lines run through what appears to be a bulkhead gasket and I thought I broke it clean off. So, I went to pull out the grommet to see if I could view the other end of the line and retrieve it. To my surprise, I ended up with the "grommet" in my hand.

Please don't laugh (I'm new here) but the "grommet" is really a feed-through connector (two sleeves on each side of the connector which hold/transition the two vacuum connections through the firewall, between the engine side and the heater switching. Unfortunately, the connector pulled free from the two lines on the backside of the firewall.

They dangle in the 1" hole - and a slight tug in attempt to release any slack comes up empty. I sense I can get 3/4" of an inch (or so) free access from the firewall, not enough to confidently be able to re-insert lines into the connector (and fearful I'll drop one/both of the lines behind the firewall hole and out of view)

I sense a complete dash removal however as the connector mounts to the engine side of the firewall, I'm struggling to understand if I can get there from the interior. Also, I tried to access the area from the hood vent and it is not possible.

Any suggestions, tips with this specific repair, or advice would gladly ease my anxiety (actually, I'm quite upset with myself, as I had the repair "bagged"..... and it got away from me!!

Thank you.
--Curtiss
2003 Ford Expedition
2001 Ford Excursion
 
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Old 06-10-2010, 10:16 PM
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Originally Posted by projectSHO89
No, you did not read that. Here is what is written:



Can't get much plainer than that without charging a flat rate fee.





Let's work on that "reading comprehension" thing.
Geez project get a life.
Don't make yourself out to be a professional.
You are far from it.
I proved you wrong in a different thread.
 
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Old 06-11-2010, 06:41 AM
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Originally Posted by stuart1
Geez project get a life.
Don't make yourself out to be a professional.
You are far from it.
I proved you wrong in a different thread.
You "proved" we have a difference of opinion, nothing else.
 
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Old 06-11-2010, 07:59 AM
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Haha, your quote here.

“It is better to keep your mouth closed and let people think you are a fool than to open it and remove all doubt.” - Mark Twain


 
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Old 04-28-2013, 08:17 PM
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chuck

I have a 2001 ford expedition. My a/c blows hot. I can change the temperature to really hot but it never goes cold. Also, when I change modes I can go from max a/c (without the cold air), a/c and vent. But panel and floor blows out defrost. Floor blows out defrost and of course you know where the defrost blows out. I don't want to tear the dash out and fix the wrong part weather it is the actual door or the motor or the actuator. How can I be positively sure once I get in there?
 
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