Theory Of Operation - Horn Relay
WARNING: This page is about a different car, the 2024 RAM ProMaster EV. However, it is still accessible from the selected car via links, so may be relevant.
The horn relay within the Power Distribution Center (PDC) switches battery current to the horn when the horn switch contacts close and provide a path to ground for the electromagnetic coil of the relay. When the electromagnetic relay coil is energized, by the Body Control Module (BCM), it draws and holds the normally open movable contact of the relay against the fixed relay contact. The closed relay contacts supply fused battery current from a fuse in the PDC to energize the horn.