Why Does the Car Key Get Hot After Being Pulled Out?

[DelLevi]

Normal phenomenon. The heating of the car key is directly proportional to exposure to sunlight. The car ignition lock is made of metal, and the hotter the sun, the more heat it absorbs. The temperature inside a closed car under direct sunlight can reach over 80 degrees Celsius. The thin car key inserted into the ignition lock will quickly heat up, causing the car key to become hot. Light above the car key slot: There is a light above the car key slot, which is not an LED and has a lower color temperature, emitting a warmer glow. After prolonged exposure, the car key heats up. Magnetic field changes: For car keys with anti-theft chips, after the key turns on the ignition switch, the factory-installed electronic anti-theft system automatically detects it. The magnetic coil inside the ignition switch generates heat due to changes in the magnetic field, causing the car key to heat up. This is a normal phenomenon. The excessive current passing through the ignition switch (large currents other than the starter motor that are not safely converted through an intermediate relay) can also contribute to the heating.