5 Symptoms of a Bad Ignition Switch
Every day, we rely on our car to start on command when we put the key in the ignition and turn the ignition switch. Unfortunately, like any other vehicle part, ignition switches can wear out. When this happens, the extent of the damage varies from case to case.
The truth is, not all ignition switches fail in the same way. Some drivers experience significant operational issues, while others experience a host of strange problems that you might not think are due to a defective ignition switch. How does an ignition switch work?
The ignition switch is directly responsible for distributing the voltage required to start the vehicle when the driver turns the ignition key.
An ignition switch typically has three separate button press positions. The first of these three positions typically provides power to the vehicle’s electrical system. The second position provides power to the vehicle’s fuel and ignition systems.
Pressing the third and final button charges the field wire of the ignition circuit to activate the starter motor. Once the vehicle’s engine starts, the driver returns the key to the second position on the ignition switch.
Symptoms of a Bad Ignition Switch As mentioned above, a defective or failing ignition switch can cause a variety of symptoms, many of which can be confusing to the average driver. The first step in solving an ignition switch problem is to recognize the telltale signs of such a defect.
1) Stalling
The electrical contacts in a vehicle’s ignition switch tend to wear down over time. When this happens, it can become very difficult for an aging ignition switch to consistently deliver the proper current and voltage required for proper circuit operation. Stalling most often occurs while driving or within a few seconds after starting off.
Many drivers overlook stalling as a symptom of a bad ignition switch because the vehicle starts as intended when the switch dictates. But in reality, the ignition switch itself is defective in the “on” position.
As a result, when the switch is in the cranking position, supply voltage is provided to the ignition system and fuel pump, but this voltage drops once the cranking process is complete.
2) Start failure
If the ignition switch in the crank position fails, you may not be able to start your vehicle. In this case, there is no audible noise from the vehicle’s starter motor. When such a fault occurs, the ignition switch is no longer able to distribute voltage to the vehicle’s starting solenoid through the circuit’s field wire. Without this signal, the starter will not operate.
3) Error in powering accessories
If the ignition switch fails in the first button-down position, it is likely that the accessory drive function is broken. This fault is not as common as the previous one, but it is certainly possible that the ignition switch is the cause of such symptoms. Excessive resistance in the ignition switch accessory area can also cause lighted accessories to flicker or dim functionality.
Some drivers choose to ignore such seemingly minor concerns, but this is never a good idea. If your ignition switch fails when you press the button, it’s entirely possible that it will soon fail further and leave you stranded.
4) Key Won’t Turn
Another symptom of a faulty ignition switch is the sudden inability to operate your vehicle’s lock cylinder with your key. If you can no longer physically turn the ignition, the internal tumblers in your ignition switch have most likely failed and will need to be replaced to restore proper functionality. In some cases, it may be possible to replace the ignition lock cylinder on a vehicle without actually replacing the system’s electronic switch.
5) Intermittent Anti-Theft Light
If your vehicle is equipped with a decoder key, the first sign of a faulty ignition switch may be the intermittent display of the “anti-theft light” when attempting to start the vehicle.
Many newer types of ignition switches are equipped with a decoder that can recognize the vehicle’s key. If you try to use the wrong key, your vehicle will electronically disable various important functions.
In this case, you will need to test the battery power of the vehicle’s remote control to rule out any issues with the driver’s key fob.