Symptoms of a bad or failing ignition switch

The ignition switch is one of the most important electronic components that is commonly found on many road going cars and trucks. It is usually located on the steering column, just behind the ignition lock cylinder. The two work together to power on and start the vehicle. The ignition switch has several positions that power on different systems as the key is turned. Most ignition switches will activate the electrical accessories on the first position, power on the fuel and ignition systems on the second position, and crank the engine on the third.

As the ignition switch is frequently used, every time the vehicle is powered on and started, it will eventually wear out and begin to have issues. Usually a faulty ignition switch will produce a few symptoms that can alert the driver of a potential issue.

1. Car stalls while driving

One of the first symptoms of an issue with the ignition switch is a vehicle that suddenly stalls while the engine is operating. If the ignition switch fails while the engine is operating it may cut off power to the ignition and fuel systems, which will cause the engine to stall. Depending on the exact issue, the vehicle may or may not be able to be restarted a short while later.

2. Car starts and then suddenly stalls

Another symptom of an issue with the vehicle’s ignition switch is a car that starts and then suddenly stalls. If the ignition switch fails at the “on” position, the position meant to power on the fuel and ignition systems, it may result in the vehicle starting, and then immediately stalling. The ignition switch will momentarily provide power to the fuel pump and ignition system when it is in the cranking position, which may allow the vehicle to start. However if it has failed in the “on” position, it will cut off power to the fuel and ignition systems as soon as the key is withdrawn from the cranking position, to the “on” position.

3. Issues powering on the accessories

Another symptom of a faulty ignition switch is trouble powering on the vehicle’s accessories. When the key is inserted and turned to the “acc” position the ignition switch should power on the the vehicle’s accessories, such as the interior lights and center console. If when they key is inserted and turned, the accessories do not power on, then that may be a sign of an issue with the ignition switch, or lock cylinder. Similar symptoms can also be caused by fuse and wiring issues, so having the vehicle properly diagnosed is highly recommended.

Ignition switches are one of the most frequently used switches on a vehicle, and as is the case with all electrical switches, can eventually wear out and require service. If you suspect that your vehicle may be having an issue with the ignition switch, have the vehicle inspected by a professional technician, such as one from YourMechanic, to determine if the switch should be replaced.