Ignition Switch – The Common Signs, Of A Failing Ignition Switch

Ignition Switch - The Common Signs, Of A Failing Ignition Switch
Ignition Switch - The Common Signs, Of A Failing Ignition Switch

Today, the ignition switch is a complex device, that powers numerous electrical and electronic systems, throughout the vehicle.

In fact, the newest version, identifies the drivers key and allows him, to activate the starting system.

One sign of a bad ignition switch, is the instrument panel not lighting up, when the key is turned. On the other hand, this could also be, the sign of a dead battery.

So, always check and confirm the battery is fully charged, before condeming the ignition switch.

The ignition switch is also used, to lock the steering wheel, when the key is removed. As a result, the ignition switch plays a key role in, keeping your car from getting stolen.

So, without the key, the switch won’t move to the start or run positions. And, will not unlock the steering wheel.

A Common Ignition Switch, Has Four Positions:

A Common Ignition Switch Has Four Positions
A Common Ignition Switch Has Four Positions
  1. OFF – Or LOCK position – Turns off power to the engine and electrical accessories.
  2. ACC – Accessory position that provides power to electrical accessories only, not the engine.
  3. RUN – The “ON” position that provides power to the engine and electrical accessories.
  4. START – Used only to start the engine.

Many cars made in the last 10 years, have a push button, instead of an ignition key. With this design, the key fob sends a signal, to the car’s computer. This signal says, it’s OK to start the vehicle. So, if everything looks good, the computer sends a signal, for the starter motor to crank the engine.

Very Few Ignition Switches, Fail All Of A Sudden

Most switches begin to fail intermittently and are usually, sensitive to temperature and humidity. If the switch fails during heavy accessory loads, the internal contacts, may have become heavily oxidized. In any case, most switches give ample warning, of an impending failure, under various conditions of temperature and load.

Common Signs, of a Failing Ignition Switch

Engine Will Not Start

The problem here is probably:

  • An anti-theft fault
  • Fault in the fuel pump circuit
  • Ignition circuit
  • Engine computer

If the anti-theft light is flashing, the computer, is NOT recognizing the key or key fob. And, is preventing the engine from starting.

Security Light On Dash
Security Light On Dash

This could be due to:

  • A bad receiver in the ignition switch that reads the key
  • Damaged smart key or key fob
  • A wiring fault, between the switch and computer

Reprogramming the computer may be required. So, the computer will correctly recognize, the smart key or key fob.

Engine Dies After Starting

  • This is one of the most common symptoms, of a bad switch. Worn contacts inside the switch, may cause a momentary loss of voltage, because of heat or vibration. So, any loss of power through the ignition switch, will cause the engine to stumble, misfire or die.

Intermittent Loss Of Lighting Or Accessories

  • A worn switch can disrupt the supply of power, to vehicle electronics. This can cause symptoms such as, flickering dashboard lights and accessories, that stop working momentarily.

Starter Motor Not Turning

  • If you turn the key and nothing happens, there’s a chance the switch, is not closing the circuit. This could stop power from the battery to the starter motor. You can test this by seeing if, other accessories in the vehicle work. When the key is in the on position, see if the radio or power windows work.

Problems Trying To Remove The Key

  • This may be due to binding, in the steering column lock. Try jiggling the steering wheel back and forth, until you feel it “click” into a locked position. You should now be able to remove the key from the switch.
  • But, if the key still won’t come out, the problem may a damaged column locking mechanism. On the other hand, if the switch is bad, the engine may keep running, after you remove the key.

Who Should Replace Your Ignition Switch

The easiest and safest way, is to take your vehicle to a repair shop or new car dealer.

Security Symbol On Dash
Security Symbol On Dash

The ignition switch on some vehicles, is part of an integrated anti-theft system. When you replace the switch, you will need to have your ignition key reprogrammed. This is normally, only available through your vehicle’s dealership. Ignition switch replacement, usually involves disabling the steering column, which can lead to unintentional airbag deployment if done wrong.


So, ignition switches are one of the, most frequently used switches on a vehicle. Worn contacts, temperature problems, or broken springs, can all cause the switch to fail, preventing your car from starting. On the road, poor ignition switch contacts, could shut the engine off while driving, which could be dangerous.

Thank You !