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Marty, Mercedes Technician
Category: Mercedes
Satisfied Customers: 53904
Experience:  Bosch Certified Master Tech. Over 35 years experience.
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How do I reset the ac compressor in order to add Freon and

Customer Question

how do I reset the ac compressor in order to add Freon and charge AC on 2003 S500 mercedes
Submitted: 1 year ago.
Category: Mercedes
Expert:  Marty replied 1 year ago.

Hi, click here for a video I made of the reset procedure. Let me know if you have any questions.

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Customer: replied 1 year ago.
Hello Marty, I did that but still did not open the compressor to allow freon in ..question do I leave the buttons out if I am trying to add freon ..expected can to get cold and nothing goes thru..I have done it before but don't remember.
Expert:  Marty replied 1 year ago.

Once you erase the codes it doesn't matter where the buttons are. You just need to make sure that the compressor is on. Are you still getting the red LED in the EC button after erasing the codes?

Customer: replied 1 year ago.
Hello Marty basically I have no light on inside the car button wise meaning all seem to be functioning fine and I have no error code all shows deleted. Also this is 2003 s500 4matic mercedes .. I did it before and it opened up for me. I wish I can recall how I did it. Maybe I should to do the erase function few times. So far ac is blowing but not cold. Also do you know if the other settings combination of other with reset button may need to be checked?? This is where I am told you check ac fan control etc says N and a number next and temperature on the right ..on general when I checked those stated average 28.6 c thanks
Customer: replied 1 year ago.
Basically when I tried to add freon does not take and cane still does not get cold I expect like last time
Expert:  Marty replied 1 year ago.

If it is blowing somewhat cold and there is no red LED lit in the display on the EC button your compressor is functioning. It sounds like there may be some other fault such as a weak compressor or a blockage in the system. Since there are no fault codes you have to look at your system pressures to see if the compressor is working properly.