What Causes a Car to Lose All Electrical Power?

The loss of electrical power in your car can be unexpected and stressful. Imagine driving it, and after a few minutes, the vehicle becomes completely dead. Initially, lights will become dim. If your car is parked, you will find it challenging to start it or not start.

You may have asked, “What causes a car to lose all electrical power?” If your car is in such a condition, you have to detect the cause of its electrical problem. Inspect the alternator, battery, ignition coil or spark plug, starter, or solenoid to find the faulty auto part. Then, resolve the issue to get your car back to life.

Why Would A Car Lose All Electrical Power?

The most significant components of a car’s electrical systems are the battery and alternator. While the battery is the to start a car, it provides the electrical voltage needed to kickstart the engine. The alternator generates low-level electricity after the engine starts running, using a rotating magnet and a bundle of circular copper wires. The electrical energy produced powers the car functions like lights, battery charging, spark, and radio.

What Causes a Car to Lose All Electrical Power

In addition to the battery and alternator, a bad ignition coil or starter can contribute to the loss of a car’s electrical power. A thorough examination of these auto parts will help you find the cause of the problem. If your battery is bad or faulty, you will have an issue starting your vehicle. However, your car will slowly lose power if a failing alternator is a culprit. In both cases, the lights fade away.

The signs of a failed ignition coil are similar to those of a bad alternator. Also, you will perceive odor or smoke. The car engine will not start, but the lights will remain bright if the starter is faulty.

Furthermore, you will hear a sound as you try to start the engine. Immediately the alternator stops working, all the components of a car electrical system will cease to function. A disrupted connection between the starter and battery or corroded cables can also cause your vehicle not to start.

What Causes a Car to Lose All Electrical Power?

A car’s electrical system ensures the smooth flow of electricity from the battery via the cables, connections, and alternator. However, the breakdown of any of the components affects electricity generation. Your car may have electrical issues if it can’t start or the lights fades away. The engine may also develop problems since it requires electricity to move the vehicle. The loss of a car’s electrical power may result from the following:

  • Faulty battery
  • Failed alternator
  • Broken connections between the starter and the battery
  • Defective starter
  • Weakened cables

Faulty Battery

A car battery will likely fail to start as it gets older, say between four to five years of usage. Charge the battery if your vehicle fails to start; it will power it. Maintain a fresh battery and keep its chargers handy to prevent an embarrassing situation if your car fails to start.

faulty car battery

However, you may need to replace the battery if the car will not start again when turned off. A whining sound indicates that the battery may no longer be functional when the vehicle is on. If your vehicle gradually loses power while driving, the alternator must have stopped working first. The battery alone cannot support the electrical system. Consequently, the generated electricity reduces until the engine stops walking and the ignition shuts off.

Failed Alternator

Though the battery is the energy source within a car, an alternator maintains its steady supply. The electricity generated in a vehicle will not be enough to power the engine if the alternator fails to recharge the battery. As a result, your car slows down to a halt if it is in motion. A failed alternator can cause your car battery to stop working.

If a car loses electrical power while driving, it indicates a faulty alternator. As alternators get older, they make a gurgling sound. You may notice the smell of hot wire as the alternator gets hotter as the car functions. The headlights’ voltage fluctuates, making them bright or dim.

Broken Connections

Over the lifespan of your car, the connections running between the battery and alternator or starter may become loose or damaged. Fortunately, the issue is easy to fix.

Defective Starter

A faulty starter will make a clicking noise when you turn your car on. The dash lights will come on if your vehicle fails to start and the starter isn’t functioning. Even a jumpstart cannot make it to start.

Weakened Cables

Your car may not start because the cables are weakened or corroded by the acid from the car battery. As a result, the wiring becomes faulty with green or white powder at the affected portions.

What to Do If Your Car Has No Power At All?

Your car is completely dead if it has no power, even with a jumpstart. There may be a power short between the battery and the dash. You can use the power probe tool to detect the connection part that lost electricity. Check the terminals of the battery. They are in good condition if they have power.

Next, find out if all the fuses in the main fuse box are blown. Inspect the wirings if the fuses are not faulty. You can check the ignition switch if nothing is wrong with the wires. It will show zero volts if it is bad when you turn on the key. You can remove the defective ignition switch and plug in the new one. Then turn on the key to power the engine.

What Electrical Problem Can Cause A Car Not To Start?

You may have a failing battery if your vehicle starts with a jumpstart. The fault may be due to its aging or underlying issues. Besides a faulty alternator, sound system, auxiliary lights, alarms, and fuses can drain a car battery. Your car battery is damaged if its terminals are corroded, and you will need to replace it.

What Electrical Problem Can Cause A Car Not To Start

You will have trouble starting your car if the alternator is faulty. The lights fade away, and you will notice a squealing sound from the engine. The noise becomes louder when you put on the sound system or heater. If the headlights are on, but the car will not start, you have to check for issues with other parts of the engine or the starter.


The signs discussed above will help pinpoint the fault if your car fails to start. You can hire a technician to check your battery and the charging and starting system. Also, an inspection of an alternator’s current and voltage output is necessary.