Do you have to??? NO!!! Should you??? YES!!!

 

First one I used a relay . Second and third no relay.

 

So I guess it won't hurt the light then just maybe the switch

 

I've been running a 30inch Cree light bar for over a year. With just a. 20a switch with a fuse


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I have a relay on my 20in but not on my 6in, no problems so far.

 

Unless its a really high amp draw light the only reason to use a relay is if your running two or more lights on one switch.:redrzr:

 

At what point or how much amp draw do you want to add a relay?

 

That all depends on the switch and wire gauge your using, with a relay or not proper wire is a must. To much amp draw will fry wire and burn out switche's. All a relay is is a switch behind the switch to keep less amp draw on the switch. And at that the relay needs proper wire. two or more lights need a relay to give proper power to both lights.

 

Ive always been told to use a relay on light bars that are longer than 12"...

 

I run my 20in on a relay like I said earlier, I disconnected my headlights and mounted a 6in on my front bumper and used the wiring that went to my headlights to hookup my 6in.it uses less watts/amps and it much better at night.

 

If you go into oreilys out on the aisles they have toggle switches that are mosy 15-20 amp switches. Behind the counter just ask for the highamp toggles which are 50-60 amp and only cost about 6$.

 

Use a good quality 20amp switch(or 30) and 12g a wire and you'll be fine.

 

If you use proper guage wire proper amp switch and proper fuse protection, I dont see a need for a relay. I mean a relay is nothing but a remote operated switch. I dont understand the need for a relay.

B.A.M.

 

Relays are used to isolate (keep separate) two different electrical circuits. The two main uses of relays are:

Use one voltage to switch a different voltage circuit. Ex: use a 12 Volt DC circuit switch to turn on a 120 VAC circuit/light.

Use a small current circuit to switch/connect a high current(amps) circuit. Ex: The low voltage switch that pulls in the high current winch motor on your SxS. Your switch and wiring are very small with low current but the wires to the winch are very large and carry a lot of current. Both are 12 VDC. The winch contactor is nothing more than a relay. Same goes with the key switch that starts your SxS. The starter contactor is a relay.

People started using relays for Off-Road lighting several years ago when the lights were big, they had a lot of them, and they would draw a lot of current/Amps. If you had a jeep with lights all over it you needed a relay for the same reasons you need one for a winch. Today’s LED lights are a lot lower wattage thus you can get by without a relay a lot of the time.

Whether you need a relay or not has nothing to do with the number of lights or the length of the lights. It is only a matter of Amp draw. If your switch can handle the Amps you are OK. A relay never hurts, it just adds one more point of failure.
Amps = Watts / Volts. Ex: 180 watt light draws 15 Amps (180watts/12V = 15 Amps)

As has been said earlier your wire has to be able to carry the current and you need a fuse. If you have a long length of wire you additionally have to consider voltage drop since this will increase the Amps (180watts/10V – 18 Amps, voltage dropped to 10 volts)

 

I use one relay to a water proof fuse box to run all my accessories. When the ignition switch is on I have 30 amps available for accessories. That way I have all my fuses and electrical runs back to a central location. Each accessory is separately fused through a panel switch. I located the fuse box in the front storage but it is small enough to locate in the glove box if you like. Makes trouble shooting and adding more accessories easy. I bought it from Amazon.
Amazon.com: Blue Sea Systems 5026 ST Blade Fuse Block with Cover: Sports & Outdoors

 

I use one relay to a water proof fuse box to run all my accessories. When the ignition switch is on I have 30 amps available for accessories. That way I have all my fuses and electrical runs back to a central location. Each accessory is separately fused through a panel switch. I located the fuse box in the front storage but it is small enough to locate in the glove box if you like. Makes trouble shooting and adding more accessories easy. I bought it from Amazon.
Amazon.com: Blue Sea Systems 5026 ST Blade Fuse Block with Cover: Sports & Outdoors

So If I am understanding correctly, your relay is in front of your fuse block? If so , then you have lead off your battery/power source to the relay, then relay to fuse block? If so what is the point of the relay if your fuse block as it own separate fuses. Just trying to understand

 

good old Ohms Law: 180watts/12volts=15amps Therefore a 20amp switch should be just fine.

 

30'' bar, no relay, no problem....yet

 

I second that notion - psheadl -

if you have a 20 amp switch and use wire that's short enough and large enough there's not much need for a relay.

But - I wanted to keep everything switched with the ignition key's accessory circuit - so if the key's off nobody can turn stuff on by flicking switches and draining the battery - etc..

So in this case - if you want to run your light bars and other accessories with your "accessory" lead from your ignition switch - use a relay to not burn out your ignition switch.

wire up the relay to use the accessory lead from your ignition switch to be the "switch" on the relay - just one extra level of security that's not needed but I think it's cool to go that way.

 

It depends on the wattage and gauge wire used.
Does your switch get hot? Than yes you need a relay or keep extra switches and possibly a fire extinguisher when the switch goes thermal.

 

It depends on the wattage and gauge wire used.
Does your switch get hot? Than yes you need a relay or keep extra switches and possibly a fire extinguisher when the switch goes thermal.

This thread is from 2014