What causes alternator to work intermittently?

If the light illuminates only intermittently, it usually indicates a loose or worn drive belt or serpentine belt, worn-out or bad carbon brushes in the alternator.

Why does my alternator only work sometimes?

Catastrophic failures are usually due to an alternator malfunction, but can also be caused by a faulty drive belt or blown fuse. A related alternator failure is the battery warning light illuminating on a random or intermittent basis because the alternator's carbon brushes are sticking in their holders or are worn out.

Can a bad alternator work sometimes?

A faulty or dying alternator may only work in fits and starts. As a result, the alternator may not have what it takes to keep your battery fully charged — even with your engine running. As a result, you may find your car stalling out at odd times.

Can an alternator go bad intermittently?

When your alternator begins to fail it can cause a variety of different electrical problems in your car, and eventually cause a breakdown. Alternators can go bad suddenly, or slowly over time.

What causes an alternator to fluctuate?

Leaking or shorted diodes can often cause a visible fluctuation in the output voltage of the charging system. Bad diodes can also allow current to leak from the battery back through the alternator to ground, causing the battery to run down overnight.

Intermittent Alternator Issue

How do you diagnose an alternator problem?

Can a bad ground cause an alternator to overcharge?

Can a bad ground cause an alternator to overcharge? It's debatable whether a bad ground will cause the alternator to overcharge. The problem is more likely to cause the alternator to undercharge, as the power is lost on its way to the battery.

How do I know if my voltage regulator is bad?

Another way you can tell the voltage regulator is bad is when the car lights keep dimming or flickering. After all, the voltage regulator is supposed to keep the power flowing to the lights, so it's no surprise that those lights don't work right anymore once this part goes bad.

Can cleaning an alternator make it work again?

Cleaning the alternators is pretty good to help maximize its performance. Nevertheless, it would be best if you do not pressure wash the alternators. Doing so can cause some serious damage to the seal, which would be bad for the car. You can rinse the alternator with some water but endeavor you let it dry too.

What happens if alternator fuse is bad?

If the alternator's fuse or fusible link is blown, the alternator will not be able to charge the battery. The battery then doesn't store enough power for starting the car or keeping it running.

What would cause the alternator to not charge the battery?

The most common reason an alternator is not charging the battery is due to worn carbon brushes or a damaged alternator itself. It can also be caused by a blown fuse or bad wirings. If your serpentine belt snapped off, the alternator will, of course not charge then either.

How do you tell if it's your alternator or battery?

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 probably your answer.

Can a voltage regulator work intermittently?

If your voltage regulator is operating intermittently, the electrical components around your vehicle will operate that way too. Whether it's your radio, dashboard lights, or more critical components like your fuel pump, you'll notice inconsistent operation.

What problems can a bad voltage regulator cause?

If you have a bad regulator, it may cause many components such as the fuel pump, ignition system, or other parts which require a minimum amount of voltage to not function correctly. You may experience the engine sputtering, a rough idle, or simply a lack of acceleration when you need it.

Is my alternator or voltage regulator bad?

When the voltage regulator is bypassed, you should see maximum voltage output. If voltage output remains at a normal level, most likely the voltage regulator is faulty. If voltage output remains at the same level (low, for example) as in your initial test (Section II, step 6), most likely you have a faulty alternator.

What happens if your alternator is not grounded?

Poor ground connections are a cause of low charging output. There are positive and negative battery cable connections, the BAT+ power connection, and the engine ground strap. Overcharging can be caused by voltage dropping on the negative side.

Will a bad ground affect alternator?

#3 – Dead Battery

Your vehicle's charging system depends on having a good ground. If the ground wire is bad, then the battery cannot be charged. What is this? Of course, another reason for a dead battery could be issues with your alternator or the wire that connects from the alternator to the battery.

What is alternator ripple?

Diodes rectify the stator's AC current into DC. Although this happens, a small AC voltage still appears at the alternator's output terminal. When properly displayed on a scope screen, this AC voltage has a rippled appearance; consequently, it's called alternator ripple. A healthy alternator can do at least two things.