Relays: What They Are & Typical Wiring Diagram

A relay is an electromechanical switch, operated by passing current through a coil of wire wound around a steel core, which acts as an electromagnet, pulling the switch contact down to make or break a circuit. These are available in several types, including SPST (single-pole, single-throw), SPDT (single-pole, double throw), DPST (double-pole, single throw), and DPDT (double-pole, double-throw), and not as commonly, in multi-circuit configurations such as 3PDT or 4PDT (three and four poles, double-throw).

In most applications, 30 amp relays have 5 connectors or wires to them. Below is a diagram of the typical wiring guide for the standard off-road lighting configuration. Application could vary per installation requirement.

Submitted by: Schitzophrynic