When do you use Relays?

[SS308]

Do you need Relay Switches when you go thru your Raptor switch panel?

I have a 52" light bar on top (roof), 30" light bar on my ADD bumper, and two floods in the front and two more mounted on the year bumper.
All going thru the switch.

Thanks for any responses.

 

[The Car Stereo Company]

anytime you reach 80% of a circuits maximum, you need relays. the equipment you have will list the amperage. compare that to the aux switch. if you are at 80%, then add a relay.

 

[SS308]

Cool, thanks!

 

[B E N]

@The Car Stereo Company nailed it. The other good use for them is if you want to run multiple items off of one circuit. Say you want all your aux lights to come on when you hit switch 4, you would daisy chain or split switch 4 into the signal section for however many relays are required. The relays also act as a "backflow prevention device" IE, you can use them to trigger a bunch of stuff that has other independent switches, without losing that independent switching.

 

[Icecobra]

Look at your amperage of your lighting and add it up. Example, 25 watt light 50 watt light 100 watt light... 175 watts total 175 devide by 13 (voltage) = roughly 13.5 amps draw. Most switches can not handle more than 5 to 10 amps. Causes switch to get very hot and fail. It's best practice to always use a relay to power auxiliary devices. The basic ones you order from amazon are usually rated 30 amps. But as stated above use 80 percent as your magic number. Once you reach 80 percent use the next higher relay. Also one switch can trigger multiple relays if needed...

 

[jondle]

I can't explain it, but I've had to put 2 relays in after years of not having them. I tested EVERYTHING with a multi-meter (amperage draw, voltage, continuity, factory relay switching, fuses) and everything logically should have continued to work without a non factory relay, but one day my lights just stopped working and about 6 months after that my lights on another switch stopped. Once I put an extra relay in, they worked again and have worked for a couple years now. I even called @The Car Stereo Company just to talk it over and make sure I wasn't crazy. Just a warning as the Gen1's start to get older, this is my experience.