DRBC43AMG

The temperatures are finally looking like real summer and with the rise of the heat I had my A/C checked and refilled. It had lost some gas since last year same time approximately. I think the compressor is getting on in age as it looks like OE factory fitted and when using a UV light, I can see some traces of the fluorescent dye around the unit. So I guess there must be a small leak, but not enough to stop proper operation.

Previously when the cabin was very hot after a spell in the sun, when I switched the engine on, the settings of the HEVAC on Auto, the fan would kick in and work up to full speed quickly. The led screen on the HEVAC control unit shows the max speed reading. A short time later after 10 secs approx, the vents would shoot out blasts of cold air over the fan's full speed, like if a second fan kicked in. This way the cabin could cool quickly and a short time later the fan would gradually reduce speed so that the occupant(s) didn't freeze!

Already last year this extra cold blast didn't work regularly. You could clearly hear it cutting in and out, but now it no longer does it.

Any ideas what could be the problem? Could it be the fan's regulator as I assume the fan has one?

I may scan and see if any codes show up

Plutoe

Read the actual data and the faults,,,,,,,postem for suggestions or continue on with your FUYAA

DRBC43AMG

And what the hell is FUYAA?

cm60k

Many things could cause this Daniel,

less or gas leak/bad tank sensors/bad Evap. indoor sensor/malfunction of climate control unit/bad compressor magnet"..!,,

did you diagnose the car..?, any codes of A/C system would help..

-;ZAYED;-

DRBC43AMG

No, not yet done any scanning. I'm a bit handicapped by a knee accident which happened yesterday evening. Walking and moving around is painful and I can't drive for a couple of days. If I can get down to the garage, I'll try scanning and pull the codes tomorrow or Friday.

cm60k

Ahh, sorry to hear that, hope everything will be okay..

-;ZAYED;-

DRBC43AMG

Thanks Zayed

brad_c43

Good luck! The heat's been getting to me down here in Florida so I replaced my evaporator last week. Not that bad of a job either

DRBC43AMG

I replaced the evaporator and dryer last year, so doubt those are the problem areas.

mickey13

my ac is out too. compressor is just a couple years old though. im taking it to a shop for diagnosis and maybe repair myself depending on what it is

DRBC43AMG

Pulled the codes this morning and nothing at first glance which would be HEVAC related. Seems the left O2 sensor is not working as it should, but it still passed the emissions test end of May.
I need to run the diagnosis of the HEVAC from the screen on the dash

mickey13

forgot about those codes... think i may have posted about that once, lets see if i can find it

DRBC43AMG

I think you may be talking about this thread https://mbworld.org/forums/c36-amg-c...control-q.html

mickey13

haha you are better than me! I couldn't find it!

DRBC43AMG

Easy, I searched on the page using the word HEVAC

DRBC43AMG

Looking in my dossier for error codes identification documentation, I came across a print-out which I pulled from this thread from 2010 ritten by our "white coat tech"
https://mbworld.org/forums/c36-amg-c...on-button.html