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2002 Mercedes-Benz E320
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Discussion Starter · #1 ·
I know my car has A/C, I don't know if it works but I have not owned the car in warm weather yet to find out. One thing I don't understand is how the A/C is turned on. Unlike every other car I've had the W124 has no dedicated A/C button. How does one activate it?
 

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1995 Benz E320
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36 Posts
My 124 has the temperature wheel that ranges from blue to white to red...I just set mine to the blue end and it blows cold air..I kinda figured that's how you turn it on, by setting the cabin temperature.
 

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2002 Mercedes-Benz E320
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239 Posts
Discussion Starter · #4 ·
I was kind of under the impression it turned on automatically at a certain outdoor ambient temperature
 

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1999 C280
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898 Posts
Like Ben said, if the EC (economy) button is pushed the A/C compressor will not engage regardless of what you set the temperature at.

Use any of the other buttons besides EC and the compressor will come on as needed.

Mark
 

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Premium Member
Current, 90 300CE, 92 400E (Sold 95 E320,70 250C, 91 190 2.6, 91 420 SEL, 95 300D, 87 TD)
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1,767 Posts
The a/c compressor turns on as needed depending on temp setting but will not turn on in EC or O mode. All other settings on most US models are auto mode unless the temp wheel is turned all the way cold or hot. I hpoe this explain your answer.;)
 

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W-1-2-3 Go!
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16,159 Posts
If you have the horizontal pushbutton unit, the leftmost three buttons will trigger the AC compressor as needed.

Left to right:

Defrost, Bi-level, Normal, EC, OFF

Defrost, bi-level and normal setting will trigger the AC compressor. Set the temperature accordingly. When Economy (EC) mode is used, only the blower is activated and fresh air is used (unless the recirculation button is depressed).

What I do, if I want AC, is to press the Normal setting (middle button) and set the temperature. If it's too far from the current cabin temp, the blower will switch automatically to high speed to cool down (or warm up) the car accordingly. If the desired temperature is near the current cabin temperature then the blower will not activate too high, but will activate only strong enough to get you to the desired temp.

If it does not work this way, something is wrong with the system. The compressor will not engage if there is no refrigerant, for example.
 

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2013 E350 sedan, 2013 E350 cab, 1993 400E sold,1999 ML320
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2,454 Posts
Most of the posts are dead on except 1, on economy the A/C compressor does cycle, just not as much and not for very long. When my system was low on freon I found this out. Switching to economy would allow me to get cooler A/C air about every minute. It would function normally in econ but would freeze up on anything else using it.

Good Luck
 

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86 300e Anke
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1,252 Posts
Most of the posts are dead on except 1, on economy the A/C compressor does cycle, just not as much and not for very long. When my system was low on freon I found this out. Switching to economy would allow me to get cooler A/C air about every minute. It would function normally in econ but would freeze up on anything else using it.

Good Luck
Sorry... gotta disagree here...

Economy setting is SUPPOSED to make do WITHOUT the compressor. :rolleyes:
And... the 'short-cycling' you mention is indicative of low freon on ANY setting, unless there is no low-side pressure switch, which is possible if it were bypassed at some point.

Before I leave work tonite I will test your statement and report once I get home.
:thumbsup:

EDIT: Yes, I enabled 'economy' and the compressor DID NOT engage. If yours does, there may be a wiring problem to look at.
:thumbsup:
 

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I know my car has A/C, I don't know if it works but I have not owned the car in warm weather yet to find out. One thing I don't understand is how the A/C is turned on. Unlike every other car I've had the W124 has no dedicated A/C button. How does one activate it?
make sure you have at least 80-90 psi of refrigerant on your low side then you will need a decent obd scanner hook up the scanner go to the air condition option and clear the code in there make sure the car in not in eco mode this will let the compressor run while you charge you system set the fan to high temp to low vent to mid and turn on the recycle air option then charge your system as normal low side 35 - 40psi and hi side varies take your outside ambient temp double that then add 45- 50 to that for your hi side psi reading
 
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