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The winter is a notoriously rough time for your car’s charging system. Maybe you’ve noticed the telltale signs that something’s wrong: dimming headlights, a hard start, or that “click, click, click” with no start at all. Batteries generally get the most attention of the components involved in charging, but what about the less talked about parts of the system? What cold weather alternator problems should you be on the lookout for this winter?

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It takes battery power for your car to initially start up, but once you get going, the engine runs the alternator through a belt and pulley system. The alternator, in turn, maintains the battery charge by feeding it regulated current. Alternators are basically mini generators that send out an AC current that must be converted to DC by a rectifier — otherwise, it could damage onboard electrical components and the battery itself. Without an alternator, you won’t be getting very far, so it’s important to pay attention to warning signs of failure: dimming lights (especially when running other components), a dashboard warning, or a weak or dead battery.

The Big Freeze

Cold weather causes problems for your battery because it must provide more juice to overcome the internal resistance of cold, thick oil. On a regular day, the alternator needs about 20 minutes of driving to fully recharge the battery, but on a cold day, it may need more time to compensate for the initial heavy energy draw. One important thing to remember here is when you’re warming your car up, give it a little rev, as some alternators need this extra jolt to begin the charging process.

The other winter alternator problem you might notice is a squeal coming from under the hood. Most often, this noise means a slipping belt. You might notice that the noise goes away after a while, and that’s because when it’s cold, the rubber belt that drives the alternator is more rigid. As it warms up, it’s able to better “grip” the pulley. If you’re hearing a squeal from your alternator belt, you’re probably not getting full charging power, and this means it’s all the more important to run your car a little longer to keep the battery charge maintained.

Power Play

How can you tell if you’re dealing with a battery or alternator problem? The one surefire way is to take it into the shop to get checked by a NAPA AutoCare technician, since there is a large margin of error when disconnecting wires on your own. If the alternator failure is due to a slipping belt, that’s easy enough to tighten, but if your problem is more than winter-related, take your car into the shop — or risk having to pay for it to be towed there later.

Check out all the electrical system products available on NAPA Online or trust one of our 16,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on winter alternator problems, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.

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