Back to all

The Power Behind your Engine (Alternator Diagnosis and Repair)

April 18, 2021

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.

Tuffy St. Johns
2770 Racetrack Rd.
St. Johns , Florida 32259
904.230.3363

More articles from Tuffy St. Johns

A Head Start on Starting (Battery Testing)

April 20, 2025

If your vehicle isn't starting or doesn't sound like it used to when you crank it, the culprit may be the battery. You may have left a light on, or something plugged into one of charging ports. Maybe you accidentally left your vehicle in the "on" or "accessory" position when you last got out. M... More

The New Blade in Town

April 13, 2025

If your windshield wipers are streaking and chattering when you turn them on in the rain or snow, it's time for a little "blade renewal." And when it comes to new wiper blades, there are some new designs that are worth a look. One of the latest is called the beam blade. It's different than conve... More

How Cool is That! (Coolant level sensor replacement)

April 6, 2025

Your vehicles engine runs hot. It should, since its a series of little explosions that create the power that gets you going where you want to go. To keep the engine cool, engineers have designed wonderful cooling systems that use liquid coolant, hoses, and a radiator to transfer the heat from t... More