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  #1  
Old 09-06-2002, 06:29 PM
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Location: Daytona Beach Shores, USA
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A/C Joke

'86 300 SDL....What a PITA. I've searched and searched for A/C and Climate Contol info. No avail. Threads peter out or if the problem is solved the person asking the question never finishes the thread to let the rest of us know if the solution worked.

My symtoms: Car sits in the garage all night. In the moring A/C works fine. All vents open and close. No vacume problem. Temp wheel works fine. Fan settings work fine. Compressor kicks in. Everything NORMAL. Even get heat in the right places if I want.

Then I park the car, get back in later, start it up, barely any cooling. Everything going to the winshield and side vents. Then eventually no A/C.

Took CC unit apart resoldered button contacts and Wheel pot. No change. Same symtoms. Anyone know what the ohm Values of the temp wheel pot is suppose to be and from which contacts (mine has 3 contacts) Driving me nuts.
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1986 SDL
My Other Car is a Porsche. When it stops leaking, I'm out of oil.
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  #2  
Old 09-06-2002, 06:50 PM
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You have an intermittant vacuum leak. The defrost position is the failure position. During such operation the recirc door, center duct, and defrost elements are all under vacuum in the A/C position. One of them is leaking or supply is faltering.
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  #3  
Old 09-06-2002, 07:11 PM
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O.K. Understand that the Failure (default) position is "defrost". If there is a Vacume leak, why no leak-down over night ? Works fine every morning on start up. What do you think leaving it overnight has to do with it ??
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My Other Car is a Porsche. When it stops leaking, I'm out of oil.
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  #4  
Old 09-06-2002, 07:48 PM
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o.k. I can see how a little leak could seal itself depending on volume of suction.

This could mean, as the car reaches operating temp, something could be happening to lower the Vacume at the source ?? Where is the Source for the CC system ? Same as the doors and locks ?

Hear comes the dreaded question...(I'm not sure I want to know).

How do I test for a vac leak in the CC system ?? Intermitant or otherwise ??
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1986 SDL
My Other Car is a Porsche. When it stops leaking, I'm out of oil.
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  #5  
Old 09-06-2002, 08:39 PM
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I think that when the car sits over night the leak is not sufficient to keep the doors from moving. Small leaks often suck themselves closed if the volume of vacuum is greater than the leak.

Later it is different When the leak gets greater the defrost position will be permanent.
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