You probably already know that a functioning alternator is essential for your vehicle to operate. That’s because the alternator is what keeps the battery charged, allowing the vehicle to turn on and run all its electrical accessories. When your alternator fails, your vehicle will not start, or it will only stay on for a few minutes. There are a few warning signs of a failing alternator that you’ll likely see before it shuts your vehicle down completely, so be on the lookout for one or more of these seven signs of impending alternator failure.

1. Malfunctioning Headlights

Are your headlights lighting up at a different brightness than you’re used to? Dim or overly bright headlights can be a sign of a bad alternator. When an alternator is failing, it can no longer provide consistent voltage to the headlights. This will make them either under-perform or over-perform. Your lights may also flicker or switch from dim to bright and back again. If you notice any changes in your headlights like this, you should take your vehicle to a mechanic to get your alternator checked.

2. Failing Electrical Accessories

Besides just your headlights, other electrical accessories can start to act up when your alternator is failing. Electrical systems such as the radio, power windows, dashboard lights, power locks, and air conditioning can all malfunction with a bad alternator because the alternator isn’t supplying them with enough power. The radio and other non-essential accessories will likely be the first to go before losing power to your headlights. While other electrical problems could also cause these systems to fail, a failing alternator is a common reason for malfunctioning electrical accessories. You should bring your vehicle to a trusted mechanic to have your alternator and electrical systems checked out.

3. Stalling or Trouble Starting

The alternator is responsible for charging the battery in your vehicle. When the alternator fails, it won’t be able to charge the battery or supply power to the spark plugs to ignite the fuel in your engine. So, if your alternator is bad, your vehicle won’t start when you turn the key in the ignition; instead, you’ll just hear a clicking sound. If you’re driving when your alternator starts failing, your vehicle might stall if it isn’t getting enough power in the spark plug to keep the engine running. When this happens, you’ll need to get the issue fixed soon or your vehicle eventually just won’t start at all.

4. Battery Warning Light on Dashboard

The battery light on your dashboard doesn’t just indicate battery-specific issues—it also lets you know that there might be an issue elsewhere within your vehicle’s electrical system. This includes your alternator. As an alternator fails, its voltage will drop below its typical 13-14.5 volts. When this happens, the battery warning light on your dashboard will light up. Your battery light can also appear if your alternator is exceeding its voltage limit. If the alternator’s voltage fluctuates in and out of its intended capacity, then the battery light may flicker on and off. You should bring your vehicle to a mechanic to inspect the alternator and check for other issues that could be causing this warning light.

5. Dead Battery

You might have a dead battery because it’s a few years old and has reached the end of its life or because you left a light on overnight. Or, a dead battery can also be a sign of alternator failure. The alternator is supposed to charge the battery while the engine is running. A failing alternator will not be able to fully charge the battery, which means the charge will run out much faster than usual. You can test if the issue is the battery or the alternator by jump-starting your vehicle. If the vehicle stays running after jump-starting it, then the issue is likely that the battery needs to be replaced. If the vehicle dies again shortly after jump-starting it, then the problem is most likely a bad alternator.

6. Strange Noises

Vehicles are known for making a lot of noises. Some are normal and harmless, while others can be signs of serious problems. When you hear an unusual whining or growling noise coming from the front of your vehicle, this can be an indicator of alternator issues. This type of noise occurs when the belt that spins the alternator’s pulleys shifts out of its proper alignment or starts rubbing against the side of the pulley. Another reason for this sound could be the bearings in the rotor shaft going bad. Any time you hear a whining or growling sound coming from under the hood, you need to get your vehicle checked out by a mechanic as soon as possible.

7. Burning Smell

A burning smell coming from your vehicle is never a good thing. If you start smelling burning rubber or wires, then parts of the alternator may be starting to wear out. The alternator’s drive belt can wear out over time from the heat of the engine and the constant friction and tension it endures. As the belt wears out, it can produce a foul burning rubber smell.

If the alternator has damaged wires or is being overworked, then it may emit an electrical burning smell. This is because when an alternator is overworked, it pushes too much electricity through its wires, which makes them heat up too much. Any time you notice a burning smell like burning rubber or an electrical fire, you should have a mechanic take a look to see if the issue is a bad alternator or another serious issue that must be addressed.

Get Your Alternator Checked at the Best Mechanic in Knoxville

If you notice one or more of these signs of a failing alternator, then you need a trusted mechanic to check out your alternator and either repair or replace it. Certified Diesel Solutions is the best mechanic shop in Knoxville, and we can provide repair services on both automobiles and diesel engines. If you think there could be a problem with your alternator or anything else, we can help. Our mechanics are ASE certified and have the knowledge, experience, and tools necessary to diagnose any issue you may be having. We will find the root of the problem then fix it to get your vehicle back in proper working order. To schedule diesel repair or auto repair services with a trusted Knoxville mechanic, reach out to Certified Diesel Solutions at 865-964-6598 or online.