Our '98 ML320 runs fine, but when we turn it off lately there has been a component that fails to shut off. Pics are attached of the part that keeps making a loud humming noise/vibration, which is under the hood on the driver's side below the windshield wiper fluid reservoir.

It will drain the battery, unless we unplug the battery cable after parking. It doesn't ALWAYS happen every time we drive, but it is very noticeable when it doesn't automatically shut off. We think it may be connected somehow to the ac/heater fan control unit. There seems to be a short and our blower isn't moving any air when we turn on the fan control.

Can you please tell me what this part is?


Thank you for your feedback

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