3 Early Signs Of Alternator Failure (And Why You Shouldn't Ignore Them)
Everything in your car ultimately runs off your engine's mechanical energy, but that energy must first be converted into electricity to power many of your accessories. Modern cars use electrical versions of critical components such as water pumps, power steering pumps, and more, making an adequate electricity supply crucial to keep your vehicle operating.
Your alternator's job is to convert your engine's mechanical energy into electrical energy. Sadly, a faulty alternator can cause numerous problems and leave you stranded. Waiting for your alternator to die can be frustrating, costly, and even dangerous, so watching for these three warning signs of an alternator on its last legs is imperative.
1. Dimming Lights
If you ask most people to describe the first warning sign of a faulty alternator, they'll probably tell you about dimming lights. A faulty alternator can cause lights to dim since it will no longer produce adequate power at low RPMs to keep these accessories supplied. You'll often notice the lights returning to full brightness as you rev the engine, another sure sign of a faulty alternator.
Unfortunately, this symptom may be a less reliable warning sign on newer vehicles. Newer cars often have far more complex electronics, with greater protections to compensate for voltage fluctuations and avoid damage. As a result, you may not notice your lights dimming until it's too late, or the lights may never dim at all.
2. Electrical Gremlins
Unusual and seemingly unconnected electrical issues (commonly called "gremlins") may be a more common warning sign on newer cars. Modern cars are highly computerized, with as many as 100 electronic control units (ECUs) controlling everything from fuel trim to transmission and steering management.
These complex computers are highly sensitive to voltage fluctuations, so a faulty alternator can result in many gremlins that don't initially seem to have any connection to one another. If everything from your electronic locks to your infotainment center seems to be suddenly acting very strangely, there's a good chance your alternator may be on its way out.
3. Frequent Dead Batteries
Your battery serves two roles: providing power to your starter to get your engine going and acting as a capacitor to smooth power delivery. Your alternator must keep your battery charged to ensure that your accessories can draw power while leaving enough juice to start your car the next morning. If your alternator can't keep your battery charged, your car won't start after you turn it off.
Frequent draining will quickly damage and destroy automotive starter batteries, so have a car repair professional check your charging system whenever your battery dies. If the alternator is bad, replace it rather than allow it to continue draining your battery. Ignoring the problem will leave you with a dead battery in addition to your dead alternator.