Relay – 800075889

A relay switches a high-current circuit on and off using a low-current control signal, letting a small input from a switch or controller operate a larger electrical load on the truck. The control signal energizes a coil that pulls a set of contacts closed, so the heavy current path stays isolated from the control side until the relay is commanded to close.

It serves in the truck's electrical system wherever a controlled circuit needs to switch a load it cannot drive directly, and it replaces a relay that has failed to pick up, dropped out, or welded its contacts. Match the coil voltage, contact rating, and terminal layout to the relay being replaced, since a relay wrong in coil voltage will not actuate and one under-rated at the contacts will not carry the load.