Can A Bad Starter Drain A Battery?

It would be an understatement to say that we heavily rely on our vehicles to get us from point A to B, maybe in support of our daily hustles, or in case of emergencies. One thing that no one would dare dispute is that vehicles have gotten pretty complex since they were first innovated.

Every vehicle in the world relies on some sort of engine. Well, except the increasingly popular electric vehicles. These engines are made up complex parts that take in fuel and air, and turn them into noise (some glorious like on a Lexus LFA) and movement. Of these parts, a failure of an important component like a starter can leave us stranded in the middle of nowhere.

So, can a bad starter drain a battery? That is a definite YES. This is actually one of the reasons people will end up replacing their batteries. A malfunctioning starter is difficult to diagnose, unless one has experience with it. Failure of the starter, shares similar symptoms with a completely drained battery, or a malfunctioning alternator.

The usual first sign of trouble is when you are trying to start your car, but then it lets out a sound like someone with a serious respiratory infection. Turning the key for a second or two usually starts the car, but then it begins taking a longer time to start.

For you to have a better idea of how to diagnose the problem, it would be prudent to take a look at how a starter works.

How Does a Starter Work?

For an engine to growl into life, it has to be spun at a certain speed. This speed allows the engine to suck in air and fuel, and then the spark plugs will cause this mixture to combust, and therefore the engine will roar to life.

The early model engines used a variety of different methods to get the engine to turn over. These included wrapping some string around a motor and pulling it away at speed. For airplanes, it included turning the propellers at speed until the engine sputtered into life.

The most common form though, was the use of a hand crank that was attached to the front of the vehicle. Drivers would need to use this hand crank to spin the motor until the engine came to life. This method had its own issues though.

As is common with engines, some kick is expected. This ended up causing serious injuries like broken thumbs, wrists and even forearms if the handle was not gripped properly. This was also a significant workout for vehicles that relied on high compression engines. These are basically diesel engines found on trucks and other larger vehicles.

The innovation of the motor to use battery power to turn over the engine, or crank it, as it is more widely referred to, saved a lot of people unnecessary trips to the hospital. The starter relies on simple principles of electricity and physics but for it to work, it requires a very large current, that’s why 12-volt batteries are the standard in cars.

When you turn the key to the on position, this allows current to flow to a solenoid, which is a part of the starter. This solenoid will then create an electromagnet. This electromagnet will attract an iron bar, which will then connect two heavy contacts. This connection completes the circuit from the battery to the starter.

This completed circuit will then force the starter motor to begin to spin. This spinning is what will start the engine. As the engine begins to spin faster than the starter motor, it will cause the connecting rod, the pinion to screw into the starter motor, thus causing the starter to disengage from the engine. This pinion is also slid into the engine by the actions of the solenoid.

A system of springs is in place to stop the iron rod from completing the circuit, and returning the key from the On Position. This is because the starter uses up a lot of battery power and must not be allowed to drain any more after the engine has started.

If the starter motor is still connected to the engine after it starts, the faster spinning from the engine is capable of causing serious damage to the starter.

How Would You Diagnose if a Starter is Draining the Battery?

Even though the universal symptom for a bad starter is a screeching sound when attempting to start the car, that sound could also signify other things. The screeching sound could simply be from worn brushes and pulley belts around the starter and the vehicles fan.

The only way a bad starter would drain your car’s battery is if you attempt to crank over the engine for a long period of time. If you had managed to start the engine earlier, turn it off and follow these steps.

Step One: For this, your keen sense of hearing will be required. Try and turn over the engine. If the engine fails to turn over, it could be that either your battery is drained or the starter could be faulty. A starter will usually let out a hum and then a click if it fails to start the engine. If you do hear the click, there is a problem.
Step Two: This test is meant to rule out the part of you battery in failing to start the car. Pop open the hood and remove the battery terminals. Start with the negative. Reconnect them then turn on your car’s headlights and cabin lights. If they are dim, then the problem is the battery. If not, the problem lies with the starter.
Step Three: This is a form of maintenance known as percussive maintenance, and it actually does work. Simply pick up a hammer or a wrench, and the lightly tap the sides of the starter. Try and start the vehicle again. If it fails then you now know the genesis of your woes.

1. Starter motor, Starting system: how it works, problems, testing –
2. How to Check for a Bad Starter on a Toyota 4Runner – It Still Runs
3. Knowing the Difference Between Alternator and Starter – KRISHNA AUTO ELECTRIC Awards