Have You Checked Your Car’s Electrical System Lately?

At AAMCO Colorado we take great care to keep you informed about your car and all its systems, as well as keep your car on the road with scheduled maintenance services and repairs, including full transmission repairs and rebuilds. Oftentimes the electrical system in your car is easy to forget until something goes wrong. Most of the time if a light goes out, it’s just a matter of changing the bulb. A little deeper issue sometimes entails a burned out fuse. But most of the time, the electrical system of your car is that silent system that is pretty much “on” all the time.

What Does the Electrical System Do?

Today’s cars are a far cry from the old days, when the most electrical things in a car were the battery and headlights. As technology, functionality, safety, and general consumer demand advanced, the need for better electrical systems and use and distribution of electricity in cars grew. Your car’s electrical system consists of three basic elements – the battery, alternator, and starter. Overall, a car’s electrical system could be considered much more than just those parts, but essentially, that’s all it takes to power your car. The battery provides power to the starter, and the alternator does the job of supplying constant electrical power as the car runs.

There are, of course, other elements, or circuits, that power the lights, electric motors, heating and cooling systems, power locks, windows, mirrors, seats, horn, radio, and of course the myriad of computers. With so much relying on the simple electrical system, it’s no wonder that when something goes wrong, it can be more than just an inconvenience. That’s when you call  AAMCO Colorado at 1-877-792-2626 or schedule an appointment online now and your nearest local AAMCO Colorado Transmission and Total Car Care center.

Causes of an Electrical System Problem

There are different signs you can look for in the event of an electrical syImage - Woman looking at engine, does not know what it is wrong.stem malfunction or failure – some problems are bigger than others. Changing a bulb is usually a DIY task, but running down a short in wiring requires more know-how and the right tools. When a light bulb burns out or a fuse blows, the circuit loses its ability to conduct electricity and stops working.

A defective battery will not charge properly, which can affect the voltage regulator and alternator. On the other hand, a consistently low battery charge might be the result of a defective regulator, alternator, or some other part in the electrical system. Sometimes a weak battery is due to a weak alternator or a parasitic drain on the system.

Low voltage can also be caused by poor connections to the battery. Intermittent electrical problems – those that come and go at random times – might be caused by loose or corroded connections. All of this can be caused by the constant heating and cooling that any car goes through in its usual operation. Vibration, moisture, and wear and tear through severe weather conditions are also factors in an electrical system’s performance over time. If you notice dim lights or solenoids failing, this too can be a sign that something is likely wrong with your electrical system.


The entire car relies on the battery for power. Basically, the battery is a power storage device used to start the engine and help operate the electrical systems and accessories in your car. It’s made up of six cells of positive and negative lead plates stacked on top of each other, separated by insulators and immersed in a water and sulfuric acid mixture (electrolyte). Each cell can store 2.1 volts of energy, for a total of 12.6 volts. Left unchecked, a weak or dead battery can wreak havoc on other electrical system parts, like alternators and starters.Prepare your car battery for cold weather

All batteries lose charging capacity over time through the loss of electrolyte, deterioration of the plates, and chemical breakdown of the connections. A decent battery should last about 3-5 years in average climates. Extreme cold or heat can reduce battery life to 2-3 years. If a car’s electrical system shows signs of a charging or starting mechanism failure, the most basic test you can perform is a visual and voltage test of the battery. Knowing the condition of the battery is the best way to know whether to suspect other electrical system components in the car are the culprit. This can save you unnecessary replacement of a starter or alternator, which will do no good until the battery is working properly or replaced. AAMCO Colorado repair centers can help with your battery issues – just call 1-877-792-2626 or schedule an appointment.


The alternator produces electricity that is stored in the battery, which in turn helps run all the electrical subsystems and accessories in the car – including the ignition and the engine control systems. It is belt-driven by the engine and produces an alternating current (AC), which is converted internally to 12 volts direct current (DC) by the diode bridge. The alternator alone can be the culprit especially in dimming lights, fading radio, and/or stalling – look for when the two conditions occur at the same time.

image - closeup of alternatorAC current is much more easily produced, but cannot be stored, which is why cars need alternators to convert the electricity to DC so the battery can hold it. Long ago, cars used separate generators to produce DC electricity, which was inefficient and could cause even more failures. Contrary to popular belief, an alternator does not constantly produce electricity. It cycles on and off, working with the battery to buffer and meet the demands of the car’s systems as they go up and down. The alternator only works enough to maintain system voltage, which means at its peak it’s charging no more than about 50% of the time.

In today’s modern cars with many extra and advanced electrical devices – running lights, continuously on headlights, super powered audio and video systems, as well as computers – the alternator and battery have to work even harder. The average lifespan of an alternator is about 3-4 years at most, which is why the alternator can easily be blamed for a dead battery. It is definitely something you want to have checked before or during replacement of the battery.


Last, but not least, the starter is used only a few times a day, but it’s the single largest power user in your car’s electrical system – and most critical to your car’s operation. The starter is a DC motor that turns the engine crankshaft through the flywheel. This initiates the combustion process by creating compression within the cylinders. The starter gets its voltage directly from the battery. This transfer of power from battery to starter is controlled by a relay operated from the key switch inside your car.

A slow cranking engine may be a sign of a bad starter. The older your car, the more likely that the starter should be checked if your car has trouble turning over, or starting at all. But on most modern cars, slow or non-starting is usually due to a weakened or dead battery, faulty electrical connections at the battery, or a failed relay or fuse.image - closeup of key in car ignition

You should start your car with major electrical components and accessories that draw power turned off (air conditioning, blower, and stereo). This will greatly ease the stress on the starter. Turning these power-hogs off before shutting off your car is always a good precaution – that way it’s just all set when you return for your next trip, and need (expect) your car to start right up!

Electrical System Maintenance & Repair

Don’t leave something as complex as your car’s electrical system to a weekend DIY project. If you are experiencing electrical system problems, get some peace of mind and bring your car to your local AAMCO Colorado Transmission and Total Car Care center for a complete Vehicle Courtesy Check diagnostic. We’ll help you keep your car running reliably so you won’t have to worry about whether your car will start in the next cold snap, or if you’ll weather the next blizzard.

If you have questions about your car’s road readiness, or about car repair and maintenance topics, AAMCO Colorado can help. You can also go online and use the AAMCO Colorado Ask a Mechanic feature to submit your auto repair questions. They will be answered by a real AAMCO Colorado mechanic as soon as possible.

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Watch this video and learn why there is only one place to go – AAMCO. We’re the transmission experts with over 50 years of experience rebuilding and replacing transmissions, and all their 800 pieces. We’ve fixed over 40 million transmissions – way more than our competitors. And we offer a lifetime warranty. Because we have the skill to fix an 800-piece transmission, we can easily fix the rest of your car – brakes, shocks, mufflers, even your engine. Lots of things can make your engine light come on. Today it can be hard to tell what’s wrong with your car, especially if it’s your transmission. Our technicians are trained to keep up with the complex engineering of today’s cars. So, next time something goes wrong with your transmission or any other part of your car, bring it to your local AAMCO Colorado Transmission and Car Repair center.