Symptoms of a Faulty Ignition Switch

Symptoms of a Faulty Ignition Switch – The ignition switch is an essential component of any vehicle. It puts on the vehicle and starts the engine.

Inserting the key into the ignition switch might feel like the simplest task to perform in your car, however, ignition switch problems can make this task very complicated.

You will have difficulties starting your car and it can shut down on the road without notice.

Ignition switch failure is one of the most commonly diagnosed causes of ignition problems and some vehicles are particularly prone to ignition switch problems.

This article, therefore explores the role of the ignition switch, its working principles, and symptoms of a faulty ignition switch among others.

Symptoms of a Faulty Ignition Switch
An Ignition Switch

What is the Ignition Switch and What does it do?

The ignition switch is a part of the ignition system and it’s responsible for starting your car and powering other components of the vehicle, like the engine and electronic/electrical accessories.

It controls the electrical accessories in the car and prevents them from draining the battery. The ignition switch connects the starter to the battery by allowing the battery to send electricity to the starter to power the car. 

The ignition switch is an essential component that helps to put the car in motion. The switch is usually operated with a key. When you insert the key in the ignition, you turn it on to power your car.

Some newer car models have replaced the ignition key with buttons, either the key or button performs the same function of giving a signal to the vehicle to begin the ignition process.

The ignition switch is mounted on the steering column, behind the ignition lock cylinder and they both work together to start the vehicle. Each time a vehicle starts, the ignition switch has been put to use making it an indispensable part of the car.

Positions of the Car Ignition Switch

The ignition switch has four positions, which include the off, on, accessories, and start positions. For some cars, the ignition switch has two off positions: one is to turn off the car while the other allows it to be locked, and the key removed.

When the ignition switch is in the off/lock position, the power supply to the engine and electronic/electrical accessories like the car radio is turned off. Your steering wheel will be locked too and you can easily remove the key from the ignition switch.

When it’s in the accessory (Acc) position, it gives power to the car accessories, e.g., radio, lights, etc. When you are in accessory mode, you won’t be able to remove the key from the switch.

The On (Run) position of the ignition switch turns on all the electronic and electrical accessories and the engine as well. The key in this position is used to crank the engine. You will not be able to remove the key from the switch at this point.

When you turn your key all the way to the Start position, it activates the starter motor and engine and allows you to crank your engine. Note that holding the key for too long in this position will damage your starter.

How does the Ignition Switch Work?

The ignition switch is located on the column area of the steering wheel and it is the first process you go through to put on your vehicle. It communicates with the control module and provides power to the engine.

As mentioned earlier, the ignition switch has four positions. The off, on, accessory, and start positions. When you insert your key, you will be able to progress from the off to the start position.

The ignition switch activates voltage from the battery to the ignition coil to create a spark in the engine. This happens when the key has been inserted. The spark from the ignition coil is sent to the spark plugs to ignite the fuel and give power to the engine.

Some vehicles have two off positions on the ignition switch. One turns off the car completely while the other allows the key to be removed from the switch.

When the switch is in accessory mode, most car accessories come on while some like window regulators stay off to prevent the battery from draining. This position uses the least amount of battery when the engine is not running.

When the switch is in ‘on’ mode, all other components are turned on including the fuel pump and the engine. The ignition remains at ‘on’ when the car is running.

When the key is moved to ‘start,’ it cranks the engine and makes the car start, then the key is returned to ‘on.’

The ‘start’ position in the switch is loaded with a spring so that the ignition does not remain at ‘start’ after the key has been released to avoid damage to the starter.

Symptoms of a Faulty Ignition Switch

Symptoms of a Faulty Ignition Switch

The ignition switch is active anytime the car is on and might begin to develop faults or wear out.

Here are the symptoms of a failing ignition switch.

The engine fails to start

The ignition switch sends power signals to the starter motor, engine, and ignition controls once the key has been inserted or the button activated.

If the ignition switch is faulty, these systems cannot receive power and the engine will fail to start.

Failure of the engine to start can be due to a defect in several components of your car and the ignition switch is one of them.

Difficulty turning or removing key

If your key is stuck and won’t turn to the other positions, or you are unable to remove it after inserting it, this is a clear indication of an ignition switch problem.

Vehicle stalls while driving

If the ignition switch is faulty, it will cut off power from the fuel and ignition systems and cause your engine to stall while it is operating.

In this situation, your car shuts off suddenly while driving. It might be difficult to restart your car after this. The car may not restart at all.

The inability of the key to activate the switch

If the ignition switch is bad, your key can be inserted and turned in the barrel but the ignition switch won’t still respond.

If the vehicle’s battery is fully charged, it’s obvious, the problem is from the ignition switch.

Dashboard light illuminates

Though this is not common for ignition switch problems. Sometimes, it happens.

When the light on the dashboard or some other electrical accessories flickers, it indicates that there’s a problem with the ignition switch’s connection plate. This can be remedied by replacing the ignition switch.

No sound from the starter motor

If you turn on your ignition switch and the starter motor does not respond, it could be a problem with the ignition switch.

This is because the ignition is unable to send power from the battery to the starter motor to put it on. Once the ignition key is activated, you are supposed to hear a little noise from the starter.

An absence of this noise means that there is certainly a problem and it could be the ignition switch.

Inability to power the car accessories

When the key in the ignition switch is moved to ‘accessory’ (acc), it powers the electronic and electrical accessories like the radio and interior lights.

If you insert the key and put the switch in ‘accessory’ mode, but the accessories are not powered, there could be a problem with the ignition switch.

Failure to maintain power

The ignition switch directly gives power to the engine, starter motor, and accessories like the headlight, interior lights, radio, window, and door locks.

If the switch is bad it will fail to power these components and your car’s performance will decline.

Causes of Ignition Switch Problems

Ignition switch problems can be caused by several factors, some of which include the following.

Inserting a wrong key

Sometimes, people with more than one car or a similar car with someone else can mistakenly use the wrong key in a car.

This is very possible because some car door locks are not so secure and can sometimes be opened with the wrong key, but when you insert such a key into the ignition switch, it can cause the ignition switch to malfunction.

As such, before diagnosing an ignition switch problem, you should confirm you are using the right key.

Worn out ignition cylinder or spring

The ignition cylinder and spring wear out over time. When this happens, the ignition switch begins to develop some fault and does not respond as usual.

At this point, it is important to replace it with a new set of locks.

Damaged key

A bent or damaged key will not function properly in the ignition lock or will be unable to turn. Some keys and ignition cylinders for certain car models are poorly designed and it leads to early key damage.

Security system problem

Modern cars are equipped with an in-built security system that allows the engine to start if the key used is recognized, to prevent car theft.

For this type of car, the keys come with a transponder chip that sends a signal to the security system when it is brought close to the cylinder. The security system then tries to match the code received with the ones that were programmed into it.

If the transponder chip is bad or there’s a fault with the security system, the engine will not start because it is not receiving a matching code. So, if this is the case, your engine will not respond when you insert your key into the ignition switch.

This problem can be diagnosed only by a professional, so it is advisable to take your car to a good auto repair shop.

Incorrect gear selector position

In automatic cars, you will be unable to turn the ignition switch if the gear selector is not in the right position.

If the gear selector is not in the ‘park’ or ‘neutral’ position, you can’t turn the switch. Some might think there is a problem with the ignition switch, but no! All you need to do is to correct the gear selector position.

Ignition switch contact problem

The ignition switch is connected to various electrical systems in the car by some contacts.

If these contacts develop a fault, it will make it difficult to start your car or can cause your engine to shut down unexpectedly.

How to Test the Ignition Switch

The ignition switch sends electrical signals to the starter motor to enable your engine to start. It controls the ignition of a vehicle and is activated once the key is inserted and turned in the ignition lock.

Before replacing the ignition switch, you can carry out a little test to decipher what the problem is.

Here is a step-by-step guide on how to test the ignition switch with a multimeter or a test light.

Testing with a multimeter

  1. Find and open the fuse panel under the steering wheel with the aid of fuse pullers, and pull out the starter signal fuse.
  2. Inspect the metal strip on the switch closely to know if it is in a good condition, if not, substitute it with another that has the same amperage as the damaged one.
  3. Open your hood and switch the knob on the digital multimeter (DMM) to the ‘volt’ symbol then connect the black lead of the multimeter to the car frame and the red lead to the positive terminal on the battery. If your battery is functional, it should be reading 12.6 volts, anything less indicates the battery is dead and needs to be replaced before going further.
  4. Insert the correct car key into the switch and try starting the engine, if the engine comes up, then your switch is functioning. If the ignition switch does not make a clicking sound or start the engine when you turn it to the ‘start’ position then there is a problem with the switch and should be replaced ASAP!


  1. Switch on the multimeter and choose the ohm function, then turn the key in the ignition switch till it gets to the ‘off’ position.
  2. Place the positive lead of the meter at the end of the ignition module’s power supply cable and place the negative lead at the distributor’s base.
  3. Turn the key in the ignition switch to the ‘on’ position and test the battery’s voltage with your multimeter. If what is displayed on your multimeter is a voltage less than 90% of your battery’s voltage, there is a problem with the ignition switch.

Testing the Ignition Switch with a Test Light

  1. Prevent the engine from starting when you switch to the ‘run’ position by turning off the ignition switch and disconnecting the module’s wire connector.
  2. Detach the ‘S’ terminal of the starter solenoid and turn the key to the ‘run/on’ position. Probe the red wire and the ignition coil’s battery terminal to the test voltage.
  3. Turn the switch to the start position and examine the voltage by probing the ignition coil’s battery terminal and the module’s wire connector.

Ignition Switch Replacement Cost

Ignition switch replacement cost varies depending on the model and makes of your vehicle.

An ignition switch costs between $20 to $50 while the cost of labor is about $100 to $200 bringing the price to $120 to $250.

Some cars have an electronic keyless ignition switch which is more expensive to fix because you will have to replace the entire ignition barrel lock. This kind of replacement cost between $400 to $1000.

Older car models are less complex and it is easy to fix your ignition switch on your own if this is the case. All you need to do is buy the ignition switch at $20 to $50 and do the labor yourself.

Frequently Asked Questions About Ignition Switch

How do I know if it’s my Starter or Ignition Switch that is faulty?

The ignition switch is located on the steering column, it activates the starter and controls the entire ignition system and electrical components of your car. Such electrical components include the radio, wiper, headlight, etc. The starter on the other hand cranks the engine which enables the car to start. It is mounted near the bottom of the car’s motor close to the transmission on the passenger’s side.

If the electrical components fail to work too as your engine refuses to crank, then the fault is from your ignition switch. If you are not convinced, you can test both components. You can test your starter by using a voltmeter to check the wires and the ignition switch by inserting the key into the ignition switch and turning it to the ‘On’ or ‘Acc’ position. From here you check if there is power in the fuses.

What happens when the Ignition Switch goes bad?

If the ignition switch is bad, it will be unable to provide power to the entire ignition system, the engine, the starter motor, and the electrical/electronic components of your car. If the starter motor is not activated, your engine will not crank, and as such your car will not have the ability to drive. A bad ignition switch will cause issues with other parts/components of your vehicle. The engine will stall, the electrical accessories won’t come on and the starter motor will not receive power to crank the engine.

Can a bad Ignition Switch cause electrical problems?

A bad ignition switch will cause a sudden shutdown and electrical problems. Your dashboard lights, interior lights or headlights will turn off at any time. Other electrical accessories like the radio, door locks, and wiper will fail to activate too.

Will a bad Ignition Switch drain battery?

A failing ignition switch will indirectly drain your battery because, in a bid to turn on the engine, you will keep making attempts that will eventually fail. Since you aren’t sure what the problem is, you may continuously make attempts to power the engine to see if it will eventually come on. This activity will drain and can even damage your battery.

Can a bad Ignition Switch cause a rough idle?

No! A bad ignition switch will not cause a rough idle. When your vehicle rough idles, it is unable to maintain a steady rotation and this is particularly caused by a disproportionate mixture of air and fuel in the engine. Rough idling is commonly caused also by dirty fuel injectors, failing spark plugs and ignition coils, a failing Positive Crankcase Ventilation (PCV) and Exhaust Gas Recirculation (EGR) valves, a bad O2 sensor or fuel pump failure.

Can you jumpstart a car with a bad Ignition Switch?

Yes, it is possible to jumpstart your car if your ignition switch is faulty. The steps to achieve this are quite simple. What you need to do is;

  • Use a jump starter or another car to carry out this process
  • Connect the positive terminal of the car battery to the positive side of the ignition coil
  • Connect the starter solenoid to the positive side of the battery too
  • With the aid of a screwdriver, connect the solenoid to the point where the ignition switch connects. Once this is completed, the vehicle will start.

Will a bad Ignition Switch cause the check engine light to illuminate?

Issues with the ignition switch or any other components of the ignition system can be detected by the Engine Control Module and this is usually indicated on the dashboard where the check engine light comes on to notify the user. A problem with the ignition system will cause the dashboard light to flicker while the engine is in motion.

What happens when Ignition Lock Cylinder goes bad?

The ignition lock is a mechanical component of your car’s ignition system, mounted inside the ignition switch which allows the vehicle to start when the key is inserted. The ignition lock cylinder utilizes electrical components in the vehicle to lock the ignition system and translate the code in the key which gives power to the engine to start. The ignition lock cylinder is made up of pins and wafer tumblers which help the key to remain in the ignition while the vehicle is in motion. If any of these components are damaged, there will be problems turning your key or the key can bend, break or fall off in the process.  A faulty cylinder will cause the lock assembly to jam when you try to remove the key.