Can a battery run down with no alternator?

An alternator that’s not providing enough power can allow a battery to run down. According to Prestolite electric, an alternator producing less than 13.8 volts of power at idle is not producing enough current to charge the battery fully and needs to be replaced.

How can I tell if my alternator is charging the battery?

Use your multimeter (if you don’t have one get one). Turn it to dc volts put your leads on your battery (with the car running), if your alternator is charging it should read from 13.5V-14.5V (thats a good charge). If your not getting a reading from there you can check your output from your alternator.

What should the voltage be on a car alternator?

12.6v is the optimal battery voltage. 13 -14v is the average alternator output. Depending on the load on the electrical system, anything higher than battery voltage is good voltage for a vehicle. Current is a different story.

What happens when the alternator of a car is dead?

The alternator and the car’s battery work hand in hand. A good battery should give you service for the next five years before its lifespan ends. If your battery is dead, then it will not give power to the car’s alternator. The alternator normally lasts longer than the battery.

When to replace battery, alternator, or starter?

When you check these three, always start with the battery. It’s most often the part that failed, and it’s also the cheapest part to replace. A car battery should last about four to five years. It is not made to hold a charge for that long, so it gets recharged by the car’s alternator while you drive.

What does it mean when your alternator goes out in your car?

So, you’ll want to check for the below signs to determine if it’s just the battery or if it’s the alternator. You can often hear a growling sound right before your alternator goes out. The smell of burning rubber or hot wires can come from your alternator overheating.

What happens to power steering after an alternator is replaced?

Usually when brakes pads are replaced and the rotors surfaced, it may make the brakes feel stiff for a while until they wear in, but it shouldn’t impact the power steering at all. The only thing I could think of… Engine sludge?

When do you need to repair or replace an alternator?

Your problem may be a worn or defective belt or a battery that is at the end of its life. If it is the alternator that is defective, then you must repair or replace it. Buyers are sometimes confused by the three “Rs” when it comes to getting an alternator fixed: repaired, rebuilt and remanufactured.

What happens if you have a new alternator and the battery is not charging?

The alternator in your car is an integral part of your vehicle’s electrical system. If you have a new alternator and the battery is still not charging, then you definitely have some kind of a problem with your battery that you’ll need to address immediately.

Can a starter and alternator be rebuilt after a fire?

While most “old” starters and alternators are rebuildable, be aware that if the casing is cracked, if the component has been disassembled, or if it has been in a fire, it will not be eligible for a core charge refund. You are better off choosing a new component.

How can I tell if my alternator is working or not?

If you’re not 100% sure, you can use a multimeter, or a voltmeter, to check the current coming from your battery. Attach the positive lead to the positive battery terminal, that’s the red one, and then the negative leave it to the black terminal. With the engine off you should be getting a reading of 12.5 volts on your multimeter.

What happens if you have a bad diode in an alternator?

A malfunctioning diode in the alternator can create a parasitic drain on a car’s battery. Diodes should allow current to pass in only one direction, but a bad diode will keep the charging circuit open even when the engine in not running, allowing the battery to go dead. This often happens overnight.

What causes a car battery to go dead when not running?

Diodes should allow current to pass in only one direction, but a bad diode will keep the charging circuit open even when the engine in not running, allowing the battery to go dead. This often happens overnight.

How can I tell if my Mercedes medic battery is draining?

Check that the glove box light does not stay on when the car is parked. The easiest way to check this is to open the glove box after the car is parked for a couple of hours. Place your hand near the glove box light bulb and feel it if it is warm. Be careful not to burn your hand. Aftermarket alarm system.

How long does a car battery last when it is disconnected?

Disconnected car battery Your battery will drain faster when it’s connected to your vehicle than when it’s disconnected. When stored properly, a detached car battery can last up to six months. Like new batteries, the key to making it last is to recharge it regularly.

What should I do if my car battery discharges?

If you don’t want to buy a memory saver now, you can use a 9V battery instead. Connect the 9V battery to the car battery terminals before disconnecting the cables. and check the case for bulging. If the battery is damaged, replace it. Also, make sure all the hold-down hardware is in place and clean the battery tray. Why Save Your Car’s Memory?

How often do car batteries need to be replaced?

A loose battery that is bouncing around can short internally, causing it to discharge. Having the positive terminal short to the vehicle body can result in a fire or explosion. And remember, batteries do not last forever. Depending on the climate and driving conditions, expect to replace your battery every three to five years.

Can a car battery go dead after a few days?

When I returned home, the battery was dead. I have never had that experience on any car ever I drove. This Instructable applies to my car, but with all of the modern electronics running in the background on today’s automobiles, your car may have this problem, too.

How do I know if it’s the battery or the alternator?

Both of these car parts control your electrical system. However, your alternator charges your battery while your battery supplies power to your car. The failures of a battery are sudden, while failures of a failing alternator are slow. Always check your battery first, it can generally tell you which of these two is the culprit.

What should the voltage of the alternator be?

What is the output of your alternator? Battery voltage measured at the terminals with the engine running should be about 13.7-14.7 volts. That is the output of the alternator at the battery and that range is needed to keep the battery properly-maintained.

How does an alternator and battery work together?

Anything less than that and your car isn’t even able to start. Both of these car parts control your electrical system. However, your alternator charges your battery while your battery supplies power to your car. The failures of a battery are sudden, while failures of a failing alternator are slow.

What happens if the alternator is not working?

The alternator charges your battery while you drive. If your alternator fails, your battery doesn’t charge and eventually dies. How long will a car run without an alternator? If your alternator isn’t working, your car can barely do more than start before you begin losing power.

Can a bad alternator kill a car battery?

A defective alternator can kill a battery if bad diodes or an internal voltage regulator prevents it from charging the battery. Or a diode can leak, allowing current to flow after the vehicle engine is shut off.

What should I do if my alternator keeps dying?

The alternator is essentially a generator and it keeps your battery charged while supplying additional electrical power for the other systems in the vehicle. If you have a new alternator and your battery keeps dying on you, then there’s definitely a problem that you’re going to need to look into.

What causes a battery light to come on after an alternator is installed?

The most common is, again, a loose connection either with the control plug (aka “relay” plug-in), charging line connection, or the ground. The other is a blown fuse or defective connector or relay, which could have been broken or shorted when the alternator was installed or on the first start-up after its installation.

Can a battery voltage test be done on an alternator?

One test is not enough if you are diagnosing a charging system problem. All too often, the alternator is condemned as the source of the problem if only battery voltage is present with the engine running. If this is the case, it only means that the alternator is not charging, but does not reveal why.

When does the alternator light turn on the battery?

On older vehicles, the battery light would turn on the alternator light when the alternator output or battery voltage dropped below a preset value. The battery light on modern vehicles, however, is controlled by data and trouble codes. This is why a scan tool is essential to diagnosing a charging system.

Why does the battery light stay on when the alternator is charging?

If your vehicle’s battery light stays on, even when the alternator is charging, it could indicate that the battery circuits or the alternator system are malfunctioning. This will lead to improper charging. Having the battery light turn on when you’re charging can sometimes happen. But the light should go off after some time.

Is the alternator the only thing that powers the car?

Many people assume that the car’s battery is the only thing that powers all electrical components in the car. But, this is not true. The alternator plays a vital role in supplying power to the car’s AC, recharging the battery and ignition.

What happens when the alternator dies on a car?

Because the alternator supplies current to the vehicle’s electrical systems, this is where you’ll notice most that something is amiss. Dead Battery: Your car battery will die without a working alternator to keep it charged. If your battery dies, you should test the battery (free at AutoZone).

What should I do if my alternator is not charging?

The alternator normally lasts longer than the battery. There are some easy steps you can go through to check the function of your alternator. Tap the alternator carefully with a hammer while the engine is runnin; if the charging goes back to normal, the coals inside it are worn out.

What causes an alternator to go over base voltage?

If you are getting more than 2 volts above base voltage, most likely your alternator is over-charging the battery or the battery is faulty. Other potential problems are a faulty voltage regulator or a problem in the charging system wiring.

Can a car battery be drained by an alternator?

While you might initially think that any problems with electrical things like lights or radio not working are directly related to the battery, the alternator is actually where most of the power in your vehicle comes from. Consider that if you were to leave the lights of your car on overnight by the next day your battery might be drained completely.

How to know if your alternator is working properly?

1 Check the drive belt or serpentine belt. Look for signs of wear or damage like cuts, shiny spots or missing chunks under the belt. 2 Also, check the belt tensioner for proper operation and damage. It should rotate freely. 3 Make sure the alternator is properly mounted. 4 Check the alternator for noises. …

Why does my new alternator whine and draw?

There are three wires going to the alternator. One red going to the back of the alternator and a red and brown going to the side of the alternator in a black connector. If I unplug this black connector amp draw/whining goes away. What could be causing this whining sound?

What to do if your alternator is over charging the battery?

Ask an assistant to start the engine and hold engine speed at about 1500 RPM. Measure voltage across the battery with your DMM. You should get 0.5 to 2 volts higher than base voltage. If you are getting more than 2 volts above base voltage, most likely your alternator is over-charging the battery or the battery is faulty.

Why is the voltage reading on my alternator going up?

While watching the voltmeter display, start wiggling wires at the back of the alternator, the battery, and the remote voltage regulator (if there is one). If the voltage reading on the meter display goes up while wiggling one of the wires, you’ve found a bad electrical wire or connection.

What happens when the diodes in an alternator go bad?

Alternators use diodes to rectify alternating current produced by the alternator into direct current. When one or more diodes go bad, the alternator can cause all kinds of problems. AC voltage leak can cause your lights to dim and drain power from your battery, for example.

Navigation