All Categories
Why we need a relay? The purpose of a relay is to switch a higher current circuit with a lower current input. For example, you could use a tine on/off switch meant to only handle 1-2 amps to power the relay and that closes the circuit on an isolated circuit of the relay that can handle up to 40 amps(big lights, for example). If you ran the small switch directly on the input of the lights, you's burn out your switch instantly. Wiring Instructions of the Relay: 87(Yellow wire) to the positive pole of the compressor. 86(White wire) to the ground. 85(Blue wire) to your original horn wire. 30(Red wire) to the positive pole of your battery.