Discussion in 'Audio & Electronics' started by Urch, Mar 14, 2019.
Can someone explain in detail why we need relays to operate aftermarket lights.
Some aftermarket lights use a lot of power or several amps. A switch and wiring would have to be heavy duty to carry this extra amp load. The relay acts as a "Go Between" where as the light duty switch and wiring only have to power the relay. Then, the relay powers on the lights using a heavier gauge wire supporting the required amp load.
Also, with a relay, you have the option to “ground trigger” the relay. Then you don’t have to. Worry about running “constant hot” wires into the cab.
Sent from my iPhone using Tapatalk
Technically, you don't need to use a relay, but if you don't, you need to use a switch and wires that will reliably carry the amps needed for the lights.
Separate names with a comma.