Can A Bad Alternator Cause Transmission Problems

Our cars sometimes face multiple problems after a long time of use. It’s understandable, as everything all goes the same way!

One of the most common failures is alternator issues with cars. Everyone seems concerned a lot as it’s a crucial part of vehicles.

Can a bad alternator cause a car not to start?” or “Can a bad alternator cause transmission problems?” frequently confused the car’s owners.

Therefore, this post will solve the questions through brief explanations and common warning signs. Now, let’s start!

Can A Bad Alternator Cause Transmission Issues?

Can A Bad Alternator Cause Transmission Problems,

Yes. Alternator issues in cars can lead to several problems, and transmission components are unavoidable.

Simply speaking, because of the lack of voltage from a broken generator, crucial parts of the transmission system that need the energy to function cannot perform well.

For instance, the power steering system, transmission control unit, etc., Eventually, the situation leads to damage to the transmission system.

Why Does A Bad Alternator Cause Transmission Problems?

The battery is recharged by the generator, which powers all the other electrical parts of our car.

Thus, if alternator problems appear, it won’t be able to supply enough power for all those components. Then, what are the outcomes?

Some electrical issues appear, such as air conditioner troubles, dimming lights, and of course, transmission issues.

There is a connection between alternator and transmission, meaning they share some cables. So, a broken alternator probably results in transmission-related failures.

In other words, the transmission control module (TCM) fault codes can be brought on by a malfunctioning alternator because this system requires power.

What Are Transmission Problems From Bad Alternators?

Some common problems can be

  • Low voltage
  • Low engine RPM
  • Fluid leak
  • Overheating engine
  • Damaged belts and hoses
  • Dim lights

When it comes to transmission problems caused by alternators, the voltage drop is the most obvious offender.

Normally, the transmission may change programming automatically to maintain low engine RPM. The purpose is to lessen the load on the engine if our voltage remains below the needed output.

Alternators with built-in voltage regulators tend to surge just before failure. It might cause unnecessary power to flow through the system.

If a surge happens, the computer may redirect power away from sensitive parts like the powertrain-control module. Finally, it might make the transmission fail.

In addition, several symptoms of malfunctioning alternators may also affect the transmission.

For example, if the alternator disconnects power to the ignition system, unburned fuel will spew out of the exhaust. It goes into the catalytic converter, leading to a fluid leak.

The worst-case situation is that a random voltage drop could deprive the torque converter lock-up, fluid controls, and transmission servos of the power.

How To Recognize The Alternator Problems In Cars?

How To Recognize The Alternator Problems In Cars?

We can count on several visible signs to determine our alternators are suffering.

Light Problems

Since alternators supply all of our car’s electrical requirements, when it starts to degrade, so do the accessories that depend on its electricity.

The automobile may begin to display unpredictable symptoms. For example, fading or excessively bright headlights, dim dashboard lights, and even speedometers that abruptly stop.

Warning Lights On Dashboard

This electrical problem can be indicated by the battery-shaped light on the dashboard.

Occasionally, it may display the letters ALT (or GEN) depending on the auto models. They mean alternator (or generator).

The car computer systems that track the alternator’s voltage output are connected to the ALT indicator. This ALT light is on whenever the electrical output is outside a predetermined range.

In other words, this light does not turn on when the output is within the stable and standard range.

Thus, if the light appears to flicker and then goes off again, it can be the early stages of alternator problems in cars.

Intermittent Stalling Or Hard To Start

One of the top signs of alternators’ trouble is a starting problem. As we’ve already mentioned before, the alternators recharge the battery spontaneously.

To ignite, an automobile begins from energy stored in the battery. If the alternator is in trouble, the battery won’t be strong enough to confidently and smoothly turn on the car.

More detail, the spark plugs may not receive enough electricity to keep the engine running. As a result, in many cases, we may still experience stalling even after the car has been running for a while.

It’s an answer to “Can a bad alternator cause stalling?” and a clear sign of alternators gradually breaking down.

A Dead Battery

According to the manufacturer, the car’s battery will take over when an alternator malfunctions or completely fails.

Batteries serve as the system’s capacitor by continuously receiving power from alternators. In this case, the battery provides all of its capacity until it drains instead.

Therefore, a visible symptom of bad alternators is dead batteries.

Belt Issues

Another generator defect can come from the belt, a crucial component in alternators. The belt may be missing, hanging from the engine block, missing, too loose, or slack.

We can check it by opening the hood. Let’s inspect the belt for signs of cracking, excessive wear, and other age-related issues that can lead to potential damages in the future.

It’s ideal if the belt is properly tensioned. In other words, too much tension is also as harmful as not enough.

Before working on anything under the hood, remember to let our automobiles cool down to avoid burns.

Strange Or Burnt Smells

After checking the above components, we should pay attention to the smell. It’s another indicator of bad alternators. Strange odors or burning smells occur when our generators are about to overheat.

It’s frequent for overworked generators to have a little electrical fire.

So, an overheated generator with high power in the rotor and stator can be the source of the burnt smell. We can feel the burning smell of rubber wires, even with smoke.

Noisy Sound

After visual and smell examinations, the sound will alert us to the presence of a failing generator. Little pop fires under the hood can make sounds.

Sometimes, before alternators fail, drivers can hear the whining and snarling noises around their engine block or wheels.


To sum up, “Can A Bad Alternator Cause Transmission Problems?” Yes! Because the alternator is crucial for all automobile operations, including the transmission system.

However, we could prevent these damages to the transmission by early determining alternator issues in cars. Let’s pay attention to the light, dashboard alerts, stalling, strange smells, etc.

From there, we can save tons of time and money on repairing the transmission system’s ruins!

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