What Is a Power Window Relay?

To fix a power window, you have to know how it's put together and whether it has a relay. Power window relays allow window operation when the car is turned off and may complicate the repair process.

Electromagnets

  • Electromagnets are only magnetic while charged. In a power window relay, the electromagnet is an iron core wrapped in coiled wire. Electricity is fed into the magnet, creating a magnetic field that lasts as long as its charge.

How Relays Work

  • Relays get their electricity from the battery. The resulting magnetic field pushes a switch into place. This switch connects the power window to the car battery for as long as the electromagnet stays charged.

What Power Window Relays Do

  • Since the relay can retain electricity in its electromagnet, it can keep the window and battery connected even after the car is turned off. The charge only lasts a short time, but long enough to roll the windows up after removing the keys from the ignition.