Air con failure
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Petrol Pete
Hardcore MB Enthusiast
How old is the car, how often do you use the aircon, have you ever had the aircon serviced ? etc etc etc .
The reason I ask is because the air con didn't get very cold on my C55 AMG so I took it for a service.
I was surprised to learn that on my engine the compressor runs all of the time unlike other cars I have had that have a clutch mechanism to 'disconnect' the drive belt from the pump when not in use. Instead the pumped gas/fluid is regulated through a valve on demand.
The upshot of this is that even if you never use your aircon a lack of fluid in the system will kill the compressor.
I am sure someone on here knows exactly how it works. Your car might have the same system.
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If the system is low on refrigerant, the car will not turn the compressor on to prevent damage
Get the car to an AC shop / Indy to have the refrigerant level checked/refilled
Get the car to an AC shop / Indy to have the refrigerant level checked/refilled
Tuercas viejas
MB Enthusiast
For info!
Later cars use on board electronic controls to maintain cabin comfort.
This is most often HVAC module electronic controlled (these days) by a variable displacement compressor. This gives better A/C comfort control and saves fuel. The most common compressors of this kind are Denso/Sanden & Harrison.
You have a Denso.
Visually you will see it has a drive pulley and what looks like a pulse clutch of old but the real gubbins of the the control is in the back where sits a further electrical socket.
This is where the HVAC control communicates with the internal shaft mounted variable swash plate that in fact controls compressor displacement and ultimately pressure and volume depending upon cooling & heating (defrost/demist) demand.
Here's a full description of operation!
If you are a gearhead like me you will find it interesting but it can get a bit technical if you are a non tech type person.
All the best
Viejas Tuercas.
https://www.youtube.com/watch?v=DPuYF0eNK6M
Tuercas viejas
MB Enthusiast
Well that is a good sign!
If its not compressing refrigerant then most likely the safety clutch arrangement at the belt has failed.
That in effect means the internals of the compressor haven't grenaded and sent metal flying through the system.
The remedy is to determine if it is actually the compressor had physically failed, the mentioned safety clutch has failed or in fact with a scanner interrogate the system and verify if the compressor is even commanded to operate.
Its not really a DIY job since several factors complicate the issue but being savvy about what is wrong helps you in making a repair decision.
The clutch failure issue is a fairly cheap repair, basically replace the compressor ,(although I have known one or two folk who have installed a clutch from a wrecked vehicle in-situ ) including a receiver drier plus drive accessory belt and tensioner pulleys etc.
The full internal grenade or reed valve failure means an extensive repair. Ostensibly replace the receiver drier and expansion valve flush it out with something like Frigiflush, and most likely replace the condenser since its internal tubes are so fine it is almost impossible to dislodge metal fragments (swarf) from the guts of the unit.
This is never a cheap option.
Then of course there is the HVAC control to scan interrogate the interface and make sure its working as it should.
Hope that helps
Tuercas Viejas
Mobile A/C certified shop owner
If its not compressing refrigerant then most likely the safety clutch arrangement at the belt has failed.
That in effect means the internals of the compressor haven't grenaded and sent metal flying through the system.
The remedy is to determine if it is actually the compressor had physically failed, the mentioned safety clutch has failed or in fact with a scanner interrogate the system and verify if the compressor is even commanded to operate.
Its not really a DIY job since several factors complicate the issue but being savvy about what is wrong helps you in making a repair decision.
The clutch failure issue is a fairly cheap repair, basically replace the compressor ,(although I have known one or two folk who have installed a clutch from a wrecked vehicle in-situ ) including a receiver drier plus drive accessory belt and tensioner pulleys etc.
The full internal grenade or reed valve failure means an extensive repair. Ostensibly replace the receiver drier and expansion valve flush it out with something like Frigiflush, and most likely replace the condenser since its internal tubes are so fine it is almost impossible to dislodge metal fragments (swarf) from the guts of the unit.
This is never a cheap option.
Then of course there is the HVAC control to scan interrogate the interface and make sure its working as it should.
Hope that helps
Tuercas Viejas
Mobile A/C certified shop owner
