W124 factory Air probs

[Anonymous]

Can anyone help with 2 probs which started at same time on my 1996 W124 E330D Estate
1. My top a/c button (air dryer) suddenly stopped working but light is still on . It used to demist the screen in seconds now its useless
2. At about the same time the temperature control of the air seems to have lost the plot and throws very hot air at you once the engine has warmed up.  Only by slamming the temp controls to minimum does it respond and then you have to fiddle around to get it right after that. I have had it regassed and it will give cold if you push the temp controls far enough  ( I never used to have to move the temp controls at all, regardless of ambient temp outside)

Merc dealer seemed pretty clueless at time of service and frankly I can't afford them to spend hours trying to track down the problem.

All advice gratefully recieved
Keith

 

[Andy]

Hi Keith,

You don't say whether the AC is actually working. If it is then the dehumidifier button should work. If not then you need to find out why the comperssor is not cutting in.

As for the heater problem. It sounds like a sticking heater duo valve problem to me.

Hope I have been some help. But without actually testing the systems its hard to say what is actualy broke.

Regards

Andy @ www.mercedesservicing.com

 

[Anonymous]

Andy , thanks for reply I have been suspecting the duo valve so time to change it I think

Re the compressor , yes it is cutting in the merc dealer did confirm that, however what used to happen was that (somehow) when you pressed that top button, there was a mechanical sound from the dash board (vacuum?) and lots of instant warm air used to hit the screen clearing it in an instant.  Now there is no perceivable activity or effect at all.

Any more clues?

 

[Andy]

Hi Keith

Your right in the discription of the dehumidifier button and its previous operation. I can't shed any more light on it. We would need to have a 1-2-1 with the vehicle.

Sorry I can't be of further help.

Regards

Andy @ www.mercedesservicing.com

 

[Anonymous]

Andy
unfortunately I'm on the Herts / Essex border so not very near to your place.  do you know of any Independent merc specialists in Herts/ Essex who might be able to assist with my dehumidifier problem
Keith