If your ignition key “sticks” or sort of makes a “click” sound when you try to turn your car on, your ignition switch is about to fail.
Heavy key chains can cause ignition switch failure, the weight of extra keys combined with bouncing while you drive or other charms you keep on your key chain can wear out the tumblers inside the ignition. This will lead to failure over time.
(The photo below is from Motor Insurance Singapore)
If you can't part with your key chain, buy one that allows you to disengage the unnecessary keys from the key chain while you are driving.
