Hi Guys! Can anyone help regarding information on my 92'W140 300SEL Rear A/C Unit is blowing Hot Air. Is there a separate evaporator and where is it located? The front A/C is working fine! Thanks guys. Can I rectify DIY or send it to a A/C shop?

There was a reason why this was so... it has been discussed before. I am curious too because the S420 does the same thing, it's never in sync with the front, if I remember correctly. I think this is normal, but, we need to know why!?

Rear A/C blowing hot air!!!!!!!!!!!
 

Hi David!
So this is not just happening to my car but typically to S-Class W140 models huh!!!!!!
So can any members advise us what's happening and what remedy to take. Appreciate you guys input. Thanks.

Chris,
Yes, I think it is supposed to be like this. I can't recall why though...? Try doing a search. I am sure someone will come along soon and help us out!

Hey David! So I am not the only one out there and thought mine have gone bonkers!!!!!!!
Say any senior members can help us would much appreciate coz everytime someone behind turns on the blower it gets me real HOT literally. Thanks again for additional input from you guys. Cheers!

Rear AC
 

Guess it's time to chime in and explain the 140 HVAC system in detail. Not all 140 chassis had the rear AC, usually just some SEL versions. If you're thinking cold air will come out from the back of the console vent that faces the rear passengers, sorry that's not rear AC but just a vent. I had the same question on mine a few years ago and was told this. The rear AC is usually another evaporator in the trunk blowing forward. Read your owner's manual for a detailed description of the system or check your trunk area.

Tobias MB
4 MBs

Hi Tobias!

Yes you are right I guess coz mine is a 300SEL model and they come with seperate evaporator for front and rear.

I suppose the rear A/C blower is out of gas or system is choked-up thus giving hot air from vent.

This looks like the job for a professional A/C man!!!!!!!!

Thanks for the info and will confirm it with my manual which is kept somewhere in the car.

Best Regards.