Hi,

I have a 97 E420 and recently the driver's side vents would blow warmer air than the passenger side when both side's temp is set to 66F. It seems that the driver's side has no feron and is blowing warm air while the passenger side is blowing ice cold air.

Anyone have similar experience? Could it be a malfunctioning A/C unit?

thanks

ED

I would try adding more freon to see if that does the trick since its cheap to do, and if that does not work, just hope its only a prob in the a/c unit it's self....that can be fixed easy....if it's anything else...RUNNN hehe....I hope things work out the best for you...You should be able to take that to a non merecedes tech....any tech will do to find this error....This will help ya save some money.

You only have one a/c compressor in the system so if you get ice cold air on one side and warm air on the other I would guess that the problem is in the control module or the blend doors that open and shut behind the dash. One side is stuck in the heat position.

I don't think its the AC unit as it responds to the temp control normally.

How do I access the blend door behind the dash?

Thanks

Ed

cabby,

you can run a flap test on your climate control panel that may help you diagnose if the problem is the blend door. Here is a link that gives you instructions on how to do it. Go down to about 3 paragraphs from the bottom and it walks you through the flap test. The embedded link to chart #2 on this page will help you read the codes.

http://www.continentalimports.com/ser_ic40142.html

did you ever get your heat problem fixed?

I have the same problem in my 01 E55. On the last service the tech responded, "They checked it out and it's not showing any codes and they just can't do anything if it doesn't throw a code."

This trip will be different. It would appear to be the left center outlet tempering flap vacuum actuator, controlled by the switchover valve unit. I'm just not sure if it controls temperature or air flow.

My 'EC' light stays on and it won't let me turn it off. If I go through like 10 different steps, turning the car on and off...EC will come off and everything will run perfectly. But it's annoying starting the car and then having to turn it back off to do this. Any ideas?

Sounds like your freon pressure is low or the sensor is bad. You should have your compressor checked. The AC unit will keep it in EC mode so that the compressor doesn't get damaged by running when it is low on freon.