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lou’s garage

I have a 2009 Mercedes B200. The A/C isn't cooling the car. - Gay

Not functioning at all? A large leak may have completely depleted the Freon charge or an electrical problem may be present.

Here are a couple of easy steps to help troubleshoot:

Start inside the vehicle, checking for proper air flow. The interior blower motor: is it spinning properly through all the speeds? If not, have you replaced the cabin filters recently? Dirty or clogged filters will impede air flow.

Move on to the underhood fuse box, checking all the air conditioning-related AC compressor and fan fuses.

The radiator will typically have two cooling fans attached to it.

Be sure to keep your limbs free for the next step. Enlist the help of a friend to cycle the AC switch on and off. Watch the fans; both should operate when the AC is engaged.

Additionally, you should be able to hear the compressor engaging and disengaging when the AC is being toggled.

About now the serious do-it-yourself types will already be filling their vehicle with some aftermarket Freon alternative.

A word of caution: discharging your AC system to the environment and/or mixing Freons is illegal in Canada.

Incorrectly self-servicing your AC system can also be a costly error.

Lou Trottier is owner-operator of All About Imports in Mississauga. Have a question about maintenance and repair? E-mail globedrive@globeandmail.com, placing "Lou's Garage" in the subject area.

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