AC not working.
MBWorld Fanatic!
Joined: Oct 2004
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From: NJ, NYC
Something Slow
Both my Ac Crap out on C240 & C320 Do you to Replace the Expansion Valve When Replacing the Compressor?
The A/C Clutch Won't Engage, I Used the SDS To Clear codes but still blowing hot Air..
The A/C Clutch Won't Engage, I Used the SDS To Clear codes but still blowing hot Air..
MBWorld Fanatic!
Joined: Jan 2005
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From: Orange County
2005 C Wagon (No snickering please!)
To Smartjay28:
The reason you cannot find the duovalve is because the W203 does not have one. The hot water flows in the cockpit all the time. Stepper motors control flaps that route the heat back outside when not needed.
It is not only a major violation of EPA rules to allow automotive refrigerants to escape into the atmosphere, the charging from cans is fraught with danger. The tech must know exactly how much to put in, by weight, and how much oil is in the system. If the system has been open, even a few seconds while swapping a pressure sensor, you must pull a vacuum for at least 45 minutes. This will boil any moisture out of the system. The drier in the system can hold only the tiniest drop of water. If you change the compressor you should also change the drier at the same time. Most home mechanics don't have a gage manifold, oil injector, vacuum pump, and accurate gram scale (although a lot of herbal medicine fellas have those) let alone a refrigerant leak detector or recycling unit and EPA license. I agree with Glyn, let the pros handle the recharge.
The reason you cannot find the duovalve is because the W203 does not have one. The hot water flows in the cockpit all the time. Stepper motors control flaps that route the heat back outside when not needed.
It is not only a major violation of EPA rules to allow automotive refrigerants to escape into the atmosphere, the charging from cans is fraught with danger. The tech must know exactly how much to put in, by weight, and how much oil is in the system. If the system has been open, even a few seconds while swapping a pressure sensor, you must pull a vacuum for at least 45 minutes. This will boil any moisture out of the system. The drier in the system can hold only the tiniest drop of water. If you change the compressor you should also change the drier at the same time. Most home mechanics don't have a gage manifold, oil injector, vacuum pump, and accurate gram scale (although a lot of herbal medicine fellas have those) let alone a refrigerant leak detector or recycling unit and EPA license. I agree with Glyn, let the pros handle the recharge.
Thread Starter
Junior Member
Joined: Dec 2004
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w203,ka7,e39
To Smartjay28:
The reason you cannot find the duovalve is because the W203 does not have one. The hot water flows in the cockpit all the time. Stepper motors control flaps that route the heat back outside when not needed.
It is not only a major violation of EPA rules to allow automotive refrigerants to escape into the atmosphere, the charging from cans is fraught with danger. The tech must know exactly how much to put in, by weight, and how much oil is in the system. If the system has been open, even a few seconds while swapping a pressure sensor, you must pull a vacuum for at least 45 minutes. This will boil any moisture out of the system. The drier in the system can hold only the tiniest drop of water. If you change the compressor you should also change the drier at the same time. Most home mechanics don't have a gage manifold, oil injector, vacuum pump, and accurate gram scale (although a lot of herbal medicine fellas have those) let alone a refrigerant leak detector or recycling unit and EPA license. I agree with Glyn, let the pros handle the recharge.
The reason you cannot find the duovalve is because the W203 does not have one. The hot water flows in the cockpit all the time. Stepper motors control flaps that route the heat back outside when not needed.
It is not only a major violation of EPA rules to allow automotive refrigerants to escape into the atmosphere, the charging from cans is fraught with danger. The tech must know exactly how much to put in, by weight, and how much oil is in the system. If the system has been open, even a few seconds while swapping a pressure sensor, you must pull a vacuum for at least 45 minutes. This will boil any moisture out of the system. The drier in the system can hold only the tiniest drop of water. If you change the compressor you should also change the drier at the same time. Most home mechanics don't have a gage manifold, oil injector, vacuum pump, and accurate gram scale (although a lot of herbal medicine fellas have those) let alone a refrigerant leak detector or recycling unit and EPA license. I agree with Glyn, let the pros handle the recharge.
When I said I'm going to replace the sensor, I mean't by going to my friends shop since he has all the need equipment to safely evac the current freon, pull a vacuum and recharge.
I had all the previous service(compressor, SAM, temp/press sensor, etc) done at a shop that specializes in Mercedes' and BMW's.
Member
Joined: Nov 2012
Posts: 119
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From: SoCal
2022 GLC 4Matic
A/C blowing, not cooling...
Mine stopped blowing cold, I was told compressor, etc.. I took the car to an Independent who ran the MBZ OBDII. Turns out it was the exterior thermal sensor not talking to the control unit in the dash. He ran the diagnostic codes and resets a couple of times, evacuated and recharged the coolant. Now still blowing cold a few months on.
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Yes ~ there is a pressure/temp sensor in the bottom of the condenser. If you don't have adequate refrigerant pressure it will shut down the system to protect the compressor.
Any problem with that sensor or no pressure & the system will not operate.
Any problem with that sensor or no pressure & the system will not operate.
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2013 UFO
So a 2002 won't fit a 2003 and vice versa?
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From: Austin, TX
2005 C230K(sold), Mk7 Jetta
Get EPC (http://epc.startekinfo.com/epc/).
Get two VINs: one from 2002, one from 2003 (google).
Log into EPC and cross-check the PNs for AC compressors.
Get two VINs: one from 2002, one from 2003 (google).
Log into EPC and cross-check the PNs for AC compressors.
MBWorld Fanatic!
Joined: Oct 2004
Posts: 4,152
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From: NJ, NYC
Something Slow
Guys, Over the Weekend I got my Compressors in both cars changed out..
First Car 2002 C240 AC wasn't working, i install a Compressor From ML320 they share the same Compressor but Different Part number :-)..after installing the Same Problem still no cold air we checked everything even Clear the codes within the SDS no COLD air.. we Applied Power Directly to the Compressor Wire and the Compressor would kick-on so it comes out that the SAM is not giving power the Compressor.
Second Car 2001 C320 With SLK32 Engine
The Install was Easier and the compressor Worked right out the Box "Denso"
so before you go changing out all unnecessary parts try adding power to the Compressor wire..
First Car 2002 C240 AC wasn't working, i install a Compressor From ML320 they share the same Compressor but Different Part number :-)..after installing the Same Problem still no cold air we checked everything even Clear the codes within the SDS no COLD air.. we Applied Power Directly to the Compressor Wire and the Compressor would kick-on so it comes out that the SAM is not giving power the Compressor.
Second Car 2001 C320 With SLK32 Engine
The Install was Easier and the compressor Worked right out the Box "Denso"
so before you go changing out all unnecessary parts try adding power to the Compressor wire..
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MBWorld Fanatic!
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2013 UFO
Get EPC (http://epc.startekinfo.com/epc/).
Get two VINs: one from 2002, one from 2003 (google).
Log into EPC and cross-check the PNs for AC compressors.
Get two VINs: one from 2002, one from 2003 (google).
Log into EPC and cross-check the PNs for AC compressors.
The post above mentions installing a compressor with a different part number but not working. Is it because the part number is incorrect?
MBWorld Fanatic!
Joined: Oct 2004
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From: NJ, NYC
Something Slow
ok so over the weekend I was working on trying to get the AC working on my 2002 C240 to recall I changed the Compressor, Dryer and I also changed the AC Pressure Sensor Switch Clear All the codes with the SDS and Still My AC is not Blowing Cold Air. but when I add 12v Power Directly to the compressor it kicks on and cold air will work.. it seems that the Front SAM is not sending power to the Compressor.. I have a SAM from my C320 Which I will Install to see if the SAM is Problem, but any help from anyone would be Great thanks...
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Wavey ~ have you charged the system with refrigerant to the correct pressure? If not it won't work to protect the compressor.
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From: NJ, NYC
Something Slow
hey Glyn, yes it was charged correctly... so it was really staring to **** me off, so after work I hook up the SDS and go thru all the coding and I found that the AC Coding was not present and some other AC coding needed to be activated, so after doing all the coding the AC now WORKS perfect....
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Joined: Dec 2006
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From: Toronto, Canada
2019 C300 Wagon; '75 Triumph TR6; previous: 2004 C230 6spd sold after 17 years of driving
my AC works really well on the passenger side but mediocre on the drivers side especially in stop and go traffic and short trips but fine on long trips >1hr then I get cold air out of both vents. I had it hooked up the star diagnostics and the tech said that stepper motors are fine, the amount of refrigerant is within specs (ie no leaks and obviously the compressor is fine as it does get cold) so he said it could be 2 things: receiver drier or expansion valve. Wondering if the great Glyn or anyone else could ring in on this. Do R/D go bad? the unit has never been serviced and since it is a closed system and I don't have leaks then the R/D should be fine shouldn't it?
Super Moderator
Joined: Jun 2008
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
It can be many things including the evapourator. We have had a lot of HVAC units do this on the forum & every time if it was not the blending flaps, stepper motors or broken arms then it was fixed by professionally recharging the refrigerant to get high side & low side pressures correct.
If it has never been done I would have the refrigerant recharged.
If it has never been done I would have the refrigerant recharged.
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Joined: Jan 2005
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From: Orange County
2005 C Wagon (No snickering please!)
They do, even if the system has never been opened. It will collect particles and in effect clog. By that time you probably have the black death, and need to replace everything the Freon touches. If the output side of the drier is cooler than the input side it is restricting the flow.
I would check to see if the fresh air door is open, and that the hot air exit is working as needed, and that there are no insects or leaves clogging the air paths.
You probably loose half an ounce of Freon per year through the hoses. Your pressures might be correct, but you could be about 5 ounces low. The only way to know is to evacuate, do an hour vacuum pull down and leak test, and recharge. Unless you are in the habit of running the A/C in the wintertime you might have o ring seals that leak a bit. The leak test should flesh that out.
Expansion valves do stick also. Often the debris from the compressor ruins them too.
Good Luck!
I would check to see if the fresh air door is open, and that the hot air exit is working as needed, and that there are no insects or leaves clogging the air paths.
You probably loose half an ounce of Freon per year through the hoses. Your pressures might be correct, but you could be about 5 ounces low. The only way to know is to evacuate, do an hour vacuum pull down and leak test, and recharge. Unless you are in the habit of running the A/C in the wintertime you might have o ring seals that leak a bit. The leak test should flesh that out.
Expansion valves do stick also. Often the debris from the compressor ruins them too.
Good Luck!
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w202
ok so over the weekend I was working on trying to get the AC working on my 2002 C240 to recall I changed the Compressor, Dryer and I also changed the AC Pressure Sensor Switch Clear All the codes with the SDS and Still My AC is not Blowing Cold Air. but when I add 12v Power Directly to the compressor it kicks on and cold air will work.. it seems that the Front SAM is not sending power to the Compressor.. I have a SAM from my C320 Which I will Install to see if the SAM is Problem, but any help from anyone would be Great thanks...
i did check the evaporator sensor, it is fine!!!
any help i would appreciate as i am desperate, it is hot in Australia
MBWorld Fanatic!
Joined: Oct 2004
Posts: 4,152
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From: NJ, NYC
Something Slow
yea mines started acting out again im getting code from SDS "Refrigerant pressure sensor" Disconnected out Open Circuit" I replace the Sensors and still the same issue im thinking the wire harness gone bad..
Newbie
Joined: Jun 2017
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W204.208 C220 CDI automatic
Hi forum
I have another annoying issue with my AC. When i turn it on it smells of sour socks for about 5 minutes. I am sure that there are some mold groving in the system but can not find any schematics to check it. My mechanic said change the iar filter and i did witout any positive result....
Anyone have a schematic or som guidance hove to clean it ?
I have another annoying issue with my AC. When i turn it on it smells of sour socks for about 5 minutes. I am sure that there are some mold groving in the system but can not find any schematics to check it. My mechanic said change the iar filter and i did witout any positive result....
Anyone have a schematic or som guidance hove to clean it ?
