Quick Answer: How Do You Troubleshoot An Alternator?

Why is my alternator not working?

The most common reason that your alternator is not charging is because of a damaged alternator.

The way to test if your alternator is damaged is by using a multimeter.

You should carefully tap the alternator with a hammer when the car is running in order to test the levels and determine if the alternator is at fault..

How long does it take a bad alternator to kill a new battery?

A 12 volt battery in most cars will run about 30 minutes to 1 hour without lights or air conditioner, since many components will run than old cars before. Starting a car takes a lot of power. You should buy a battery with more power or fix your alternator.

How long can you drive with a bad alternator?

Starting with a fully charged battery you will probably get 100 Miles before it wears down too far. It also depends greatly on not running headlights or running lights. If you have a car that always runs with the headlights on, and if your battery is several years old, 50 miles might be a better estimate.

Can a bad alternator destroy a new battery?

Yes. The alternator can have a bad diode which allows A/C to flow to the battery. It does not take long for A/C to damage battery cells. Likewise, a bad battery will kill an alternator.

What happens if alternator fuse is blown?

#3 – Blown Fuse Once that happens, the alternator will no longer charge the battery. Not all vehicles have these fuses, so you will have to check your owner’s manual to see if your car has them. If so, this is well worth investigating in the event your car battery is not charging properly.

How do you know if it’s your battery or alternator?

If the engine starts but dies immediately, your alternator probably isn’t keeping your battery charged. If a jump starts and keeps your car running, but the car can’t start again off of its own power, a dead battery is likely your answer.

How much does it cost to replace alternator?

Waits says the average price to replace an alternator with a remanufactured one is $400, while Gunning adds that a remanufactured alternator on a typical, domestic car, costs about $300 to $500, including parts and labor. The price of a new alternator can run from $500 to $1,000.

What kills a alternator?

One of the most common failures is bearing failure. The needle bearings that allow the rotor to spin freely inside the stator can break down from dirt and heat. When the bearings fail, the rotor will not spin efficiently and can eventually seize. Usually an alternator with bearings failure makes a loud grinding noise.

What happens when alternator goes out?

The alternator provides power to the spark plugs that ignite the gasoline in your engine. When the alternator is failing, there might not be enough power in the spark plugs to keep the engine alive, which can cause it to stall for no reason while running, or to have trouble starting.

What would cause a good alternator not to charge?

Hi There, The first diagnosis of the bad voltage regulator is likely the cause of your charging system not properly charging the battery. … In other cases it may result in the alternator not supplying enough power to the battery, resulting in undercharging the battery or not charging it at all.

Can a car run with a bad alternator?

In short – yes, but It’s not recommended to DRIVE a car with a bad alternator, here’s why: Your car’s alternator is the main power feed for the car’s electrical system when the engine is running, the battery is only designed to be used as a power source to start the engine.

Does an alternator just stop working?

The alternator is responsible for providing power to your car’s different electronics. Things like power windows and power seats might start operating at a slower speed than normal or stop working altogether. A dying alternator may also cause your car’s radio and internal lighting to stop working.

What does a bad alternator sound like?

The grinding sound may be caused by a worn-out bearing. Your car can also make a whining sound when the voltage regulator is sending signals to the alternator to charge more than is necessary. If you hear any type of whining or grinding sound that’s a good indication that your alternator needs to be checked.

How long does it take for a bad alternator to kill a battery?

20 to 30 minutesIf your alternator is going bad, the vehicle will shut down after 20 to 30 minutes. The alternator, as it fails, will drain the battery, causing all electrical systems to power down. Look at the dashboard when you turn the headlights or radio to the “On” position.

Can you test an alternator by disconnecting the battery?

If you’re tempted to test an alternator by disconnecting the negative battery cable, don’t do it. A good alternator may indeed keep the engine running without the negative cable, but this was never a good test. … The second you disconnect the battery, the voltage regulator pegs the alternator to put out maximum power.

How do you check if your alternator is bad?

A battery test is easy to perform and can be done at home. First, open the hood and start the car. While the engine is running, remove the negative cable from the battery. If the vehicle stalls or dies, the alternator is likely bad.