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

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

Keep Your Cool in Sterling Heights

May 31, 2026

Sterling Heights drivers rely on their vehicle's coolant system to keep their engine cool. Coolant (also called antifreeze) mixed with water flows through your vehicle engine and absorbs heat. The mixture then flows out to the radiator where it's cooled by air flowing over the radiator. From th... More

Coolant/Antifreeze Service in Sterling Heights, Michigan

May 24, 2026

Sterling Heights auto owners may know that most automotive failures in Sterling Heights, Michigan, are tire related, but do you know the second most common cause of vehicle failure? Nope, it's not teenagers. It is the coolant system. But if you take good care of your vehicle coolant system, it ... More