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Q: Economy Mode light won't turn off on 1997 Mercedes-Benz S420

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After I turned the AC on, the Economy Mode light cannot turn off. I tried to turn it off by disconnecting the battery, but the light stayed on. I also tried turning the heat on and off so as to reset it but it stayed on. According to the manual, when that light is illuminated, the AC compressor turns off. The EC light can be turned off by pressing the button, which I tried as well but the light is there. What else can I do?

Thanks for writing in about your 1997 Mercedes-Benz S420. This is a warning from the system telling you that there is a problem that must be serviced. You should have the light looked at by a professional so they can inspect the system for the fault causing the climate control to function improperly. In some cases, a low refrigerant charge from a leak can cause this problem.

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