W210 Aircon Compressor not engaging

[w210inSpain]

Hi

My aircon was working fine, and desperately needed at the moment!
It has worked fine all morning today, but on the way home for dinner, a loud clattering sound started, I turned off the blower fan to hear it and it stopped, and started again when I turned the fan back on. I left the fan off until I got home.
I checked under the bonnet while the wife turned the fan switch, and the compressor clutch was going mad. Rapidly clicking in and out, but not staying engaged.
Is this a fault with the compressor or is there a relay which may be at fault not holding the clutch engaged?
Any help will be appreciated, or the wife is threatening nasty things!!!!

Pete.

 

[Blobcat]

The clutch won't engage if there is low/no gas.

 

[w210inSpain]

Thanks for the reply Blobcat.
Since yesterday we´ve tried the aircon again, there were a couple of loud knocks from the clutch and then it engaged! Today it has been working fine!
Possibly some dirt in the clutch? not sure, or could it possibly be a poor earth? I´ll have a look at the weekend but at the moment it looks ok, phew! (fingers crossed)
Would be interested to know if anyone else has had the same though.

Pete.

 

[w210inSpain]

Unfortunately the same problem started again today.
Aircon was working fine this morning. Then compressor started rapidly cutting in and out again. I´m hoping it may be an earth problem or a voltage problem as when the engine revs increased it cut in and worked. When the engine dropped to idle the noise returned.
I just need some time to be able to investigate!! The wife is using the car constantly!
Pete.

 

[w210inSpain]

Went to the Merc dealer to get a price for the compressor, ouch €1200! Noticed the clutch kit came separately, another ouch €600!
So, I trawled the internet. Found a company called coolcaraircon.co.uk fantastic, bought the compressor and a new dryer for about €450. Brilliant service, posted to Spain for me, and arrived here within a week. Got my local garage to fit it, and all working well. The new compressor even had the merc labelling and part number on it.
Definately recommend them to anyone, all makes and models and most aircon parts.

Pete.

 

[Blobcat]

Excellent news, little need for AC here at the moment, although it is useful for dehumidifying the air ;-)