Starter and Alternator Inspections: Keeping You Moving in Cold Weather

“Chilled to the bone” for humans means “chilled to the electrolyte” for vehicles. Most of us don’t jump out the front door, raring to go when winter is showing off at -15 ˚C outside. Your vehicle’s electrical system can empathize.

To start, here is how your vehicle’s electrical system runs:

1. The engine supplies power to the alternator.
2. The alternator charges the battery.
3. The battery supplies your vehicle’s electrical system with energy.

In this article, we’ll focus on difficulties you may encounter with your starting system and the alternator. You can find more information on how cold weather affects your battery here.

How Cold Weather Affects Starting Systems

When you turn your key in the ignition or press the start button, you engage the starter motor. This is not the main engine, but instead, a small motor solely responsible for turning the engine on. (The more technical term you may here is “cranking the engine.”)

The starter motor must draw its energy from the battery to get your engine running. Once the engine is on, your vehicle’s electrical system will follow the process we described in the beginning.

Here’s where problems can arise:

• A vehicle’s battery loses up to 35% capacity at -18 °C. If you take too many short trips in such cold weather, or you try to crank your engine too often, you risk draining your battery.
• The oil that runs through your engine becomes thick in colder weather, making the starter work harder to turn the engine.
• The alternator has to work harder to recharge a cold battery.

In addition, moisture and road salt can affect the electrical connections in your vehicle. Your heater, defroster, lights, and windshield wipers also create a heavy load on the battery.

Signs Your Starter Is Having Difficulties

You should never repeatedly turn on your vehicle. If it doesn’t start within 10 seconds the first time, wait 30 seconds before trying for another 10 seconds. If you can’t start your vehicle after three tries, stop and call a tow truck to avoid damage.

If you can start your engine, look out for these other warning signs that point to a problem with your starter:

• a single loud click when you turn the key
• rapid clicking sounds
• grinding or whirring noises
• slow engine cranking
• the dashboard lights work but the engine won’t start
• intermittent starting
• smoke or burning smell (requires immediate attention)

Any time you hear strange noises in your vehicle, don’t chalk them up to “personality” or “quirks.” Something isn’t working, and an inspection may save you a lot of trouble and money down the road.

Signs Your Alternator May Need Attention

Remember that the alternator moves the energy your engine makes to the battery to charge it. If you notice any of the following signs, you may have a problem with your alternator:

• The battery warning light on your dashboard stays illuminated.
• Your headlights dim or flicker, especially when you’re idling.
• Electrical accessories are acting erratically.
• Your battery repeatedly goes dead.
• You smell burning rubber.
• You hear unusual noises, such as growling or squealing.

An alternator’s expected lifespan is about seven years, so it may simply be time for a replacement. However, whether your alternator is nearing its end of life or is malfunctioning, it will eventually leave you stranded once your battery has died. Have it inspected immediately.

What to Expect at a Professional Inspection

A licensed automotive technician will conduct several tests, most of which require specialized equipment. A few examples:

• Battery: Does the battery voltage differ when the engine is off and then turned on?
• Starter: How much current does the starter draw when it’s turned on?
• Alternator: How does the alternator’s output change at various RPMs?
• Serpentine belt: Is there any visible damage? Does it still have proper tension?

Automotive technicians will also check all electrical connections and terminals for corrosion and other signs of visible damage.

You’ve Found a Problem. Now What?

Call your local NAPA AUTOPRO service centre to ask about the best way to bring your car to the shop. Some symptoms still allow for a short drive, whereas others (like burning smells) require a tow truck. With your vehicle safely in the garage, one of our friendly technicians will be more than happy to help you.