The working principle of automotive relays mainly utilizes the principle of electromagnetic induction, which generates a magnetic field through the electrification of the coil, thereby controlling the closure and disconnection of the contacts. Specifically, when the coil is energized, it generates a magnetic field, and the moving iron is attracted to drive the contact spring, causing the static contact point to separate and the moving contact point to close. When the current of the electromagnetic coil is cut off, the iron core loses magnetism, the moving iron core resets under the action of spring force, the moving contact opens, and the stationary contact closes.