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Q: Resistors on AC stay on - 2002 Mercedes-Benz

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My air conditioner only worked periodically in my car, so I replaced the cabin air filter and removed leaves and dirt from the blower motor. It didn’t help at all. So I bought a new blower motor resistor and the air conditioner worked on all the settings. But when I took the key out of the ignition the fan stayed on and wouldn’t turn off. I replaced this resistor with a new one and it still did the same thing. Do you know what’s wrong? Could it be that both resistors were no good?

A: Hi there. If the fan is staying on when the...

Hi there. If the fan is staying on when the vehicle is turned off, then it may have a bad connector at the resistor. It is common for these resistor connectors to melt and cause this to occur. If the connection is fine, then it may have a relay that is sticking but that is not as common. I typically do a circuit test with a voltage meter to see where the problem lies. If you are going to have this fixed, consider YourMechanic, as a certified mechanic can come to your home or office to inspect the AC problem and guide you with a repair.

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