Sherwood

I have an LED light bar that draws 75 Watts and two KC Apollo lights that draw 200 Watts combined.

The LED light bar came with its own wiring harness, and the KC lights come with a harness also. I've decided I want to wire all of these lights to a single 3 way rocker switch, and have the option of turning them on/off with the high beam switch or on/off regardless of headlights. I think I have a handle on how to wire it using two relays etc.

My main question is: can I power the LED light bar with the same circuit that will power the KC lights? The KC lights will draw more than double the current of the LED bar, so will this distroy the LED bar or will it still only draw what it requires?

I've calculated that 10 AWG wire and a 30/40 amp relay should cover the amperage of this setup, does that sound reasonable?

byte

200 watts is 17 amps... 75 watts is another 6.2 amps... both harnesses and tie the trigger for the relays to the switch together

Sherwood

hah, amazing, I just talked to the guys at work about this today and we came up with exactly the same solution. Props to you man, I figured this thread was a dud.

I think I'll have one relay that is triggered by the switch, and another relay in series that is triggered by the high beams. If the switch is in the ON position, then the highbeam switch will turn the aux lights on and off too. If the switch is in the OFF position the highbeams can be used by themselves.

Long story short, I can control the aux lights with the highbeams or I can use the highbeams by themselves. I can't use the aux lights by themselves though. Not a big deal

PS, fellow Albertan by the way

byte

find your high beam power source... run that to the switch... other side of switch goes to trigger on relays

benchwarmer4203

If you use a single pole double throw (SPDT) switch you only need one relay and you'll have the function that you described in your original post. A SPDT switch is also known as an On-Off-On switch. Basically one "On" position of the switch would trigger your relay using the high beam signal and the other "On" position would trigger the relay with 12V regardless of the high beam status.

Edit: To reduce some of the loading on the relay, it probably wouldn't be a bad idea to feed the light bar and the halogens with independent relays; but if you want to keep it simple a single relay is most likely going to be rated for that much load.

Sherwood

Excellent. So I'm guessing there are two "On" positions and a center "Off" position? This sounds like a good route to take. I was actually already considering using separate relays for each since both came with their own wiring harnesses I can put to use.

benchwarmer4203

Yep, that's how it'd be set up. Let me know if you have any questions once you get started.

arent_we_sarcastic

Don't forget to fuse each line separately for the lights ( 1 - 20amp fuse and 1- 7.5amp) after the relay and one (30 amp) between the relay and the battery