• An ignition switch refers to two components of a vehicle's ignition system. The first component is the lock cylinder. The keys used to start the vehicle are inserted into the lock cylinder. The second component is an electronic switch located directly behind the lock cylinder. In some vehicles, these two parts are separate, and in some they are combined. When an ignition switch goes bad, certain symptoms will be present.
  
  

Engine Symptoms

• A bad ignition switch can cause a vehicle to suddenly die, according to Goldwing Tech. This can happen as the vehicle is traveling down the road. It often occurs intermittently and without warning.
  
  

Accessory Symptoms

• According to 1A Auto, accessories, such as the radio and windshield wipers, may suddenly stop functioning properly. In some cases, this problem is intermittent, and in some cases it is permanent.
  
  

Lock Cylinder Symptoms

• When a vehicle has a bad ignition switch, the lock cylinder may need to be manipulated excessively to start the vehicle, i.e., jiggling this component when inserting the vehicle's keys and starting the engine.
  
  

Other Symptoms

• A bad ignition switch can cause a vehicle with power to not produce any noise from the starter when the vehicle's keys are in the "Start" position.