Have you ever gotten into your car, turned the key, and nothing happened? Most people would think that the battery is dead. There are many things that can prevent a car from starting. However, there is one possible cause that is often overlooked: it could be the switch that helps distribute the power from the battery. If this has happened to you, check the ignition switch.
Evolution of the Ignition
The first gasoline-powered cars required multiple steps to start the engine. The ignition was activated with a rotary ignition switch among other things. After the birth of the car key, it was only used to lock an electric circuit to the engine. Drivers still had to use the manual process to start the car. By the 1920’s, the ignition switch was used to lock the circuit, ignite the starter, and lock the doors.
Modern internal combustion engines need a mixture of air and fuel in order to start. The air/fuel mixture is ignited in a combustion chamber. The ignition process starts when you turn the key in the ignition. The ignition switch is a part of the ignition system.
The ignition system is comprised of a few components contained in an ignition assembly which work together to start and stop the engine. The system is controlled by the vehicle’s computer, which sends signals to start the ignition process. The computer usually has a built-in chip which communicates between the parts. The computer also depends on the crankshaft sensor for information about the ignition system control.
The ignition coil and the distributor make up the distributor portion of the ignition system. The ignition coil is an electronic component that is designed for some degree of management of the engine. The coil is the part of the ignition system that takes power from the battery and converts the voltage enough to jump the spark plugs to ignite the air-fuel mixture. The ignition coil is made up of a primary and secondary winding. The primary winding takes the power and the secondary winding distribute it. There is also a distributorless ignition coil that is characterized by one ignition coil for every two cylinders. The distributor receives the voltage and distributes it among the spark plugs according to a specific timing.
The ignition switch, also called a starter switch, is located in the steering wheel, When the key is inserted and turned, the switch is turned on and off. The ignition switch gives power to a starter solenoid, the ignition coil, and the engine control unit. Many newer cars do not have a key at all; but rather, a button and remote controller communicate with the computer to start and stop the ignition process.
The ignition switch controls much more than the startup and cutoff of power. It also controls the accessories in your car, such as the radio and electric-controlled windows. The typical ignition switch has four positions:
- Lock/Off – When the ignition switch is moved to the Lock/Off position, it turns off the power in all the circuits and locks the steering wheel mechanically. In a vehicle with an automatic transmission, the ignition switch also locks the transmission gear selector. The ignition switch must be in the Lock/Off position to remove the ley out of the ignition.
- Run – In this position, the ignition switch provides the power to all the components in the ignition system. The circuits are fed by the ignition switch without the starter motor. The computer quickly prepares the engine to start. If the ignition switch remains in this position for too long, the battery will drain faster.
- Accessory – In this position, the ignition switch turns on power only to the accessories. The dashboard lights, the radio and power windows will work but the engine does not come on.
- Start – This position actually starts the engine as well as powering the accessories. You can charge your phone while listening to the radio while you drive in this position.
You choose an ignition switch position by turning the ignition lock cylinder. The key must be inserted in the ignition.
Symptoms of Bad Ignition SwitchThe ignition switch has such a big job that it can be the first component that needs to be replaced. Because the key is turned in the ignition so much, the switch often goes bad. Here are the most common signs of a bad ignition switch:
Engine won’t start – The ignition switch supplies power to the engine controls and the starter motor. When the ignition switch goes bad, the components do not receive the power. Electricity that runs through to the sensors and the computer are be blocked or shorted when the wires are damaged. Some components will not receive sufficient voltage or may not receive any electricity at all. When this occurs with the ignition switch, it can prevent your car from starting at all.
Powering accessory problems – You may notice that your power windows won’t go up or the radio won’t come on when the ignition switch goes bad. The dashboard lights may flicker on and off. These parts are not receiving power either, or at least not enough power.
Car won’t start – When you turn the key in the ignition, the car won’t start. You don’t even hear the sound of the starter motor. The internal contacts inside the ignition switch may be worn down. Again, the engine is started by power distributions and the igniting of the air/fuel mixture. If the ignition switch is bad, the power is not being distributed.
Key hard to turn – When the ignition switch is bad, you may notice turning the key in the ignition is hard to do. The key may feel as if it’s wriggling inside the keyhole. The first thing to check is the condition of the ignition switch.
Car won’t shut off – Some issues actually keep the engine running when you try to shut it off. If the car won’t shut off, then for some reason, the ignition switch and the fuel system are not getting the message to shut down. The air/fuel mixture in the combustion chamber is still being ignited by a hot spot instead of a spark inside the combustion chamber causing the engine to jerk and rock (dieseling).
Stuck key – The ignition switch can go out at the most inopportune times, including when the key is in the ignition. Depending on what position the switch was in when it died, you may not be able to remove the key.
Stuck steering wheel – There is a mechanical lock located inside the ignition switch that locks the steering wheel when the car is parked. When the ignition switch goes bad, the steering wheel may be stuck in the locked position.
Test the Ignition Switch
You can test the ignition switch before you go to the trouble of starting the engine without it. There are a few methods for testing the switch:
Multimeter method –
- To use this method, you must be able to turn the ignition switch off
- Connect the positive multimeter (view on Amazon) probe to the ignition switch power feed wire.
- Connect the negative probe to any metal part.
- Turn the key to the run position. Set the multimeter to measure voltage.
- Read the voltage. Any result that is less than 90% battery voltage means the ignition switch is probably bad.
Test Light method –
- Use a 12V test light to test the switch.
- Turn the key to the off position.
- Disconnect the module cable connector.
- Disconnect the starter motor solenoid S terminal.
- Turn the key to the run position.
- Connect the red wire to test the voltage.
- Connect the red wire to test the ignition coil battery post.
- Put the key in the start position.
- Connect the ignition switch white wire.
- If the lamplight does not come on, the ignition switch is probably bad.
You Need to Know This About Your Ignition Switch
If the ignition switch is bad, then its a sign that you’ve been failing to maintain your vehicle. Maintaining things like your battery and other parts of the vehicle will allow the ignition switch to function properly over a long period of time. If not, the ignition switch will go bad and you won’t be able to turn on your car’s ignition. This can cost a lot to repair so it’s best that you avoid it in the first place.
If you want to avoid ignition switch problems or other issues and save $100s of dollars that you’ll spend at the auto repair shop, you’ll need to service your vehicle often – you can use our mechanic-rated Auto Maintenance and Repair Manual to do this. It’s basically what mechanics use to go through your vehicle to check if there are any problems that need fixing. As soon as they notice the most minor problem, they’ll ask you to fork out some money even though it’s a problem you can fix yourself in minutes – the manual will teach you how to maintain your vehicle every few thousand miles and it’ll teach you how to fix minor problems that mechanics will ask you to pay for; saving you money in the long run.
A lot of our readers have the Auto Maintenance and Repair Manual printed on their garage wall and 92% of them haven’t visited the auto repair shop in the last year because they know what to do to avoid problems. All it takes is giving your vehicle a little attention every few thousand miles and you’ll never spend money at the workshop again.
Start the Car with Bad Ignition Switch
A vehicle with a bad ignition switch should be repaired right away. By driving it anyway, you are taking a chance on becoming stranded and the car won’t start. However, the switch could go bad at a bad time and you need to bypass the switch and start the car. You may need to crank the car and drive it to a garage. In this case, here’s how you can crank the engine with a bad ignition switch:
Jumper cable method – Many automotive services and repairs require things like battery testing, using jumper cables. Instead of hooking the cables to the battery terminals, you will hook one cable to the positive battery terminal and connect the other cable to the ignition coil:
- Open the hood and find the battery and the ignition coil. Connect the positive cable to the positive side of the ignition coil. It is of paramount importance that the battery terminals and the jumper cables are matched up with the components.
- Find the starter solenoid and connect it to the positive battery terminal.
- Unplug the ignition switch wiring from the starter solenoid. Use a screwdriver to short the solenoid positive terminal to the same post that the ignition switch connects to.
- Try to start the car.
Drill and a Screwdriver Method – This method works; however, you must be careful not to damage the ignition switch:
- Find the keyhole.
- Use a metal drill to drill into the keyhole until you have drilled the same length as the key so as to break the internal pins in the ignition cylinder.
- Insert the screwdriver in the keyhole and turn the ignition. The car should start up.
Hotwire Method – This method works if your vehicle was manufactured before the mid-90s:
- Find the steering wheel column.
- Remove the plastic cover that keeps all of the internal components in place.
- Find the wiring harness connector. If you are not sure how to find it, refer to your owner’s manual. It should be in the middle of the steering column.
- Now find the battery, starter connectors, and the ignition. The wires should be color coded: red for the battery, yellow and brown for the ignition.
- Strip the battery wires down one inch from the insulation. Twist the wires together.
- Connect the ignition on/off wire to the battery wire. The lights should come on in the dash.
- Strip the starter wire down about one half inch and connect it to the connected battery wires. The engine should start up.
Starting your car without the ignition switch is only a temporary solution. If the ignition switch has gone bad, have it replaced as soon as possible. Get back on the road and drive safe.