Back to all

The Power Behind your Engine (Alternator Diagnosis and Repair)

September 20, 2020

There's nothing like that sinking feeling when you turn the key and nothing happens in your vehicle.  A lot of us are quick to blame the battery.  But it may instead be your alternator that's failing.

Your battery supplies power to start your vehicle, but the alternator is what sends power when your engine is running.  The good news is alternators last a fairly long time, and it's not unusual to get seven years out of one. But they can give up the ghost thanks to the harsh conditions in the engine compartment.

Alternators have bearings inside them that keep things turning smoothly.  Debris, liquid, dirt and more can team up with the high temperatures your engine generates to cause those bearings to seize up.  That's not good, and if that happens, you may even be able to hear the bearings grind.

Other symptoms of a dying alternator are a squealing noise in the engine compartment or your headlights may go dim and bright, dim and bright.  You might even notice an electrical smell.  Any of these signs warrants a trip to your service facility.

Here's something else to think about.  If your alternator's bearings have seized up and the unit's shaft is not turning freely, that can destroy the belt that's attached to it.  So don't be surprised if your service advisor says both parts have to be replaced. 

There are different grades of alternators you can buy, but consider just how important this part is to keep your vehicle running.  Your service advisor will give you options based on your driving style and vehicle.  Remember, if you notice any of those symptoms that may signal a failing alternator, have it taken care of before you wind up stuck somewhere at the side of the road.

Sterling Tire & Auto
34701 Van Dyke Rd
Sterling Heights, Michigan 48312
586-264-7775

Need Service?

Request a Quote

More articles from Sterling Tire & Auto

Timing Cover Replacement

June 21, 2026

Your engine has a lot of parts that need to work in harmony in order to keep you powering down the road. Some of those parts need to be protected in order to keep things running smoothly, and one that does the job is called a timing cover. It is in the front of your engine and shields components... More

No Charge (Why Won’t My Battery Hold a Charge?)

June 14, 2026

When your vehicles battery is dead, it leaves you with that horrible, helpless feeling. A dead battery means it wont hold a charge, and there are several reasons it wont. One is age. Batteries have chemical and electrical systems in them that create power, and as time goes by, they wont work we... More

Knowledge is Power (Battery Testing)

June 7, 2026

Its likely happened to you once or twice. You head to your vehicle, open the door, turn the key and lo and behold, your battery is dead. Now youre stranded, may have to get a jump or a tow, and youll definitely be late for wherever you were headed. While your vehicle may sometimes give you warni... More