air con problems

[rondeauteller]

Hi everyone,

I currently have a c220 (W204, registered 2010) During the winter my air con ceased to operate. It does not work at all (i.e. does not blow any air no matter what setting you choose). Having done some investigation i thought it would be either the blower motor or the blower/heater resistor.
I removed the blower motor and connected it to and independent electrical source and it worked. So i naturally assumed that the blower/heater resistor was defective. I replaced this item and fitted it today. I reconnected all of the electrical fittings and switched the ignition on but sadly it still did not function.
I was wondering if anyone had any ideas why my air con should still be not be working?

 

[zipdip]

Welcome to the club,well have you had the air con regassed,

 

[Petrol Pete]

Welcome to the club,well have you had the air con regassed,

Fans should still run even with zero gas pressure. You have not mentioned checking the fuses ? I assume you did that first.

 

[rondeauteller]

Hi both,

Thank you for your views. I have had the system re gassed and i have also checked all the fuses. Sadly the system is not functioning and i`m at a loss to figure out why it doesn`t work. My next plan is to remove the air con control panel and see what i find?

 

[Deleted member 131833]

Have you tried a search for diagnostics using the car? On the CL you can diagnose faults using the buttons.

On CL you press rest and air pollen filter and hold for 5 seconds to go into diagnostics. Then any fault codes are shown and option to clear codes

Might be worth searching before you start dismantling

 

[alabbasi]

Put gauges on and see what the pressure readings are and then get back to us. Your a/c is a sealed system. If it needs gas, there is a leak.
I don't see how people on this forum think that it's possible to diagnose a/c problems without proper manifold gauges. The force must be strong with them.

 

[rondeauteller]

Thank you both for your replies.
I`m a little confused ref using the buttons to diagnose the fault, my system just has the air con button, off button, Max button, heat window button, fan button and upper or lower blower button. Do not have pollen button or filter. I then have the circular knobs at both ends for driver and passenger to control the temp. If you could explain further that would be great.

Ref the A/C system i took it to a well know garage in these parts who checked the system for leaks and regassed the system. They informed me that there were no leaks and it still did not work after the re gas. They suggested it might be an electrical fault hence my decision to remove the heater control panel and see if any of the wires have come loose etc.

 

[Deleted member 131833]

Well, Al you have got me really confused, below is your quote when I asked about my aircon problems

You can go on youtube and look up W220 ac trouble shooting. The digital display will throw codes that you can look up and there's a guy from the UK who did a good job of documenting how this works. If you have an a/c charge and no a/c, your compressor may have failed. This happened to my S55 and it was all kinds of fun getting it replaced.

I did as you suggested found the file and used it to troubleshoot my aircon, worked a treat.

I only suggestedroneauteller try the same on u tube hoping that a similar solution would be found for his car, my thinking being that Merc would apply this to all mercs not only the CL


So the force is strong with me!

 

[alabbasi]

Well, Al you have got me really confused, below is your quote when I asked about my aircon problems
I did as you suggested found the file and used it to troubleshoot my aircon, worked a treat.
I only suggestedroneauteller try the same on u tube hoping that a similar solution would be found for his car, my thinking being that Merc would apply this to all mercs not only the CL
So the force is strong with me!

Thanks for your response. I was not responding to your post directly but instead reacting to the general practice of trying to diagnose a/c problems without a set of manifold gauges. They are fundamental to the process like a microscope would be fundamental to the job of a micro biologist (probably, I have no idea what a micro biologist does). The W220 offers some good built in tools for detecting hard sensor faults through the control panel which is great, but it won't tell if your level is low (the W210 digital panel does), how much to fill with or if you have a faulty expansion valve etc.

Using Youtube as a learning tool is a great suggestion. I'm sure that there are videos available on how to use manifold gauges. As a matter of fact, here's one I made earlier

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[Deleted member 131833]

Found this on a search on the inter whatsit

How to Reset a Mercedes AC System

1. Insert the key into the Mercedes ignition and turn the ignition cylinder to the "2" position. ...
2. Press and hold the defrost and recirculated air buttons simultaneously. ...
3. Wait 45 to 60 seconds for the LED lights to stop flashing. ...
4. Wait 60 seconds and then start the car engine again.

Might be worth a try, same problem as mine, solved by following advice from Al, maybe just needs reset?

 

[rondeauteller]

Alabbasi,
I think you my have posted your reply on the incorrect thread?

I have tried to reset my Air con system without success. I plan to revert to plan A and take out the main air con knobs and push button switches and see what i can find.

 

[alabbasi]

Alabbasi,
I think you my have posted your reply on the incorrect thread?

I have tried to reset my Air con system without success. I plan to revert to plan A and take out the main air con knobs and push button switches and see what i can find.

Thanks, I'm not sure which post you were referring to but please see post #6. The point I was making is that if your a/c has stopped working, first thing should be to put gauges on. Gauges will tell you if you have a problem with the pressure switch, blocked expansion valve and low freon.

The next comment was in response to post #8

Thanks

 

[Smart320]

Suspect when you dismantle your controls all you will find is that you cannot do anything other put it back together ! I would be straight down to an air con specialist who will have the expertise be able to identify the fault ( once you have put the controls back together ).

 

[markjay]

...my air con ceased to operate. It does not work at all (i.e. does not blow any air no matter what setting you choose). ...

From the way you describe it, the fan does not work at all?

If so, does it not work only when the AC is turned on?

Or does the fan not work at all, i.e. it does not blow air under any setting, cold or hot?

I am trying to understand if you have a fan issue, or an AC issue?

 

[BIG UN]

Pressure Switch?? They are prone to fail on the Viano/Vito which will stop the A/C from working.