Intermitent Air Conditioning W126,Why?

[Finny]

The air conditioning on my W126 works (Climate control version), although it is not particularly cold.

However I have noticed that if I turn it off while driving. Either EC or OFF. Then while driving I try to put it back onto air conditionting - Nothing.

Fan is working, however no cold air, just circulated normal air and a bit musty spelling and stuffy.

I have found that slowing down or stoping the car does nothing. However if I turn the car off, and then turn it back on (With air cond in On position), the air conditioning will be working again. Not really cold, but it is working ?

I know it may have a leak and/or need gas.
So the question is, what is turning the car off doing ?
Why won't the air cond turn back on again while the car is running and how do I fix it.

 

[Finny]

Tried this again today, turned the air conditioning off and then back on again. This time it kept working.

Any ideas ????????

 

[Finny]

Does anyone have ar conditioning ?

 

[jaymanek]

I have the same system but all I can think of is some sort of electrical issue... relay maybe?

 

[lynall]

Cause weve all got air but we dont need it to keep cool we use it to demist the car

I reckon you need a regas iirc air con systems san lose up to 10% of their gas per year due to natural leakage.

Also low pressure will switch the ac off so you me be right on the point of just enough pressure then not enough so switching the sytem off.

Lynall

 

[scotth_uk]

Finny, have a read through google - I had a W126 which displayed similar traits. Turns out that there are mountains of information about how there are likely to be issues such as dry solder joints behind the panel, dodgy fuse holders that cause intermittant starts, etc. Some of the american forums were excellent for this information.

 

[compress ignite]

Try Here

I've taken the liberty of reposting your question over on mercedes shop.
You can Look over there with this link for answers:
http://mercedesshop.com/shopforum/showthread.php?p=2125955#post2125955

First I'd get the Gas Pressure "Up to Par".
You are Resetting "Something" by turning the Ignition Off + then On.