Adding led lights...relay or not

[jcummins]

I'm wiring these into a John Deere 855d....standard headlights quite poor.

Should I or do I really need to use relays?

For this... Amazon.com: Auxbeam™ 12" 72W CREE LED Work Light Bar 7200lm Combo Beams 24pcs 3W Cree Chips Waterproof for Jeep off road Van Camper Wagon ATV AWD SUV 4WD 4x4 Pickup Van Off-road: Automotive

And for this...Amazon.com: JACKYLED 2 Pcs 7inch 36W 4000 Lumen CREE LED Work Light Bar Flood Beam 4X4 Offroad Lamp Spot Lights for Vehicles SUV UTV Jeep Truck Boat: Automotive

Both on separate switches.

 

[Looking4new]

A relay will protect the switch.

 

[Paystar]

Not really needed. My 80W LED spot and flood lights only draw 3.69 amps each.

 

[jcummins]

These lights not like days of old. They really don't draw many amps.

BUT I don't see in any of the documentation at Amazon exactly what they do draw. No further documentation came with the lights.

 

[DT86]

I run relays for the purpose of having the LED lights shut down with the key (RTV) and headlights/key (tractor). Both are still on toggles.

 

[jcummins]

I run relays for the purpose of having the LED lights shut down with the key (RTV) and headlights/key (tractor). Both are still on toggles.

I was going to just tap into power that is behind the key, that way they go off if key is off.

 

[DT86]

I was going to just tap into power that is behind the key, that way they go off if key is off.

That works too if you can determine the load and if the source can handle it. I could never figure either so I went the way I did to be sure.

 

[aczlan]

I was going to just tap into power that is behind the key, that way they go off if key is off.

Use a relay then.

Aaron Z

 

[PILOON]

The majority of toggle switches will handle 10 amps at 12 volts DC.
A few major brand names will go 15 amps.
That is for the normal size vs the mini styles.
With most LED systems I would not hesitate to switch direct DC without using any relays.
I even switched dual 3" halogen spots with a standard toggle.

 

[TomSeller]

If you are going to tap after the key so the lights go off with the key, then I would absolutely use a relay and fuse the circuit. The key switch is not intended to power large auxiliary loads directly.

 

[oldpilgrim]

I wouldn't be surprised if the relay drew more power than the led lights.

 

[TomSeller]

I wouldn't be surprised if the relay drew more power than the led lights.

If it did, the wrong relay was selected.

 

[jcummins]

If it did, the wrong relay was selected.

So relays are not all the same? Educate me on the relay I should use.

I'll actually tap to the back of the headlight switch since they go off when the key does, and it will be right beside each other.

 

[MF283]

Keep the answers coming folks, want to add lights to the new 550 & this thread is greatly appreciated, thanks jcummins for starting it. BTW, i hate fooling with electronics, so the easiest way to do this is....................

Ronnie

 

[Garandman]

Many motorcycles run 12V lighting directly through the switch. PILOON nailed it.

I ran mine through the work light circuit, switched directly for one 36W light.

 

[jcummins]

Here is the switch I'm using. It's a 20amp switch.
Amazon.com: E Support Car Blue LED Bar Light Toggle Switch: Automotive

The reason I've asked these question in the first place, I can't clearly understand how many amps these lights draw.
Adding a relay actually could man the install cleaner, wires are going to route right past the battery. So relay needed are not, fairly easy to do. But it adds cost.

Anyone clarify the amps these things will draw?

 

[Wild Bill the 2nd]

Watts / Volts = Amps
72 / 12 = 6
36 / 12 = 3

So with all of the lights you are looking at you will only be at 12 amps. The switch will handle it just fine. Now the trick will be finding a circuit on the vehicle that will handle the extra draw.
I like to take the draw back to the fuse box where you might be able to tap into an empty lug on the switched side of the box. Mind you, I'm not tapping into a fused circuit, I'm going to the main bus bar. The new line needs an in-line fuse.

I used these switches on my tractor light install. I had to go to the fuse box with the front lights as they drew nearly 25 amps. For the rear lights I tapped into the existing wiring since they only drew 3 amps.

 

[aczlan]

Here is the switch I'm using. It's a 20amp switch.
Amazon.com: E Support Car Blue LED Bar Light Toggle Switch: Automotive

The reason I've asked these question in the first place, I can't clearly understand how many amps these lights draw.
Adding a relay actually could man the install cleaner, wires are going to route right past the battery. So relay needed are not, fairly easy to do. But it adds cost.

Anyone clarify the amps these things will draw?

You don't need a relay to protect that switch, it will be fine running the lights directly. The relay is to protect your ignition switch so you don't melt it or start blowing fuses (if you are still pulling power from your ignition switch).

Aaron Z

 

[davesl708]

These lights not like days of old. They really don't draw many amps.

BUT I don't see in any of the documentation at Amazon exactly what they do draw. No further documentation came with the lights.

To determine the amp draw divide the watts by the voltage. Example my 18 watt Cree lights should draw no more than 1.5 amp. Actual amp test showed .7 amp draw.

 

[TomSeller]

This is would be how I would do it. The relay is just like your solenoid on your starter (the "solenoid" is a "relay"), it carries the heavier current. I would put the relay under the dash. The idea is that the added LED circuit would not draw power from the key switch itself. If your LED or the WIRING going to it shorts out, you don't want the key switch to carry that load (expensive to fix if that circuit's fuse is oversized). The wire going up on the ROPs or where ever likely is exposed to tree limbs or whatever hitting it and shorting it to your negative frame.