Back to all

The Power Behind your Engine (Alternator Diagnosis and Repair)

October 4, 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.

Tuffy Joliet (South Plainfield)
2031 SR 59
Joliet, Illinois 60586
815-436-1829

More articles from Tuffy Joliet

It's (Not) Complicated (Engine Air Filter)

March 29, 2026

While many components of your vehicle are complex and composed of lots of mechanical and electrical parts, there's one that isn't complicated but still important. It's your engine air filter. (And, we should point out, the engine air filter isn't to be confused with the cabin air filter. The ca... More

The Last Gas (Fuel Pump Replacement).

March 22, 2026

You're heading down the road and you notice your vehicle is sputtering, like it's running out of gas. But the gauge show's it's still got a quarter of a tank. So what gives? It could be that your fuel pump is failing, meaning your engine is not getting enough gas to run properly. While fuel pu... More

Don?t Skip Out on These! (Vehicle Maintenance Items You Should Never Postpone)

March 15, 2026

Maybe that little sticker on your windshield is giving you the reminder that its time for your vehicle to have an oil change. Youve thought, Aw, I can skip this one and save myself a little money. When it comes to things you should never ignore on your vehicle, timely oil changes are number one... More