Wire LED light bar

[markyezy]

Hello all,

 

I have a 2019 Silverado - I installed the RoughCountry 10" LED bar in the grille as well I installed 2 10" Rigid SR Pro lights behind the grille

 

I was to wire these all up onto one switch that is also connected to the bright lights - so if the switch isnt turned on no light bars if the switch is on and the brights are activated the light bars will all come on.

 

Looking for some help, is there a wire harness that has 4 plugs to it? If I need to run my own wires what gauge should I be using? What should my fuses be?

 

Thanks all

Mark

[CRApex]

I would connect your power supply/ground to the battery through a relay, have the high beams activate the relay and maybe a toggle switch wired between the high beam connection and relay.  This would only keep the lights off if you didn't want the high beams to activate them, you couldn't just turn the lights on with the switch..but I think that's what you're looking for.

[kodiakdenali]

There are a couple of places where you can get high beam activation signals. on the BCM there is a wire that gets ground when the high beams are on, this is what turns the relays on in the under hood electrical center.

module X5 (brown) pin 18, brown/violate: high beam relay control.

you could tap into this wire, run it through your switch and then through the firewall to one side of your relay coil. in this case the other side you would connect to 12V. whenever the switch is in the on position, high beam circuit will activate the relay and turn on the light bar.

another option is at the under hood electrical center itself. there are 2 fuses for the high beams (see the diagram in the manual or under the fuse box cover) the relay for the high beams is before the fuses, so the fuses have 12V only when the high beams are on. you could use an add a fuse type product (micro-ATC type) to get that signal, and use that to activate your relay. in this case though to have it switched you'd have to put the switch between this point and your relay, so you'd have to run 2 wires through the firewall. in this case the first option is actually easier.

either way you setup the relay to be activated the contact side of it would be the same, a suitable high current power source (fused) to one side of the normally open contact, and the other side to your light bar's positive wire.

 

wire size and fuse rating depends on how much current your lights draw (combined). This information should be in the documentation that came with them, or they might have come with fused wiring that would be a good indication as to the fuse capacity you need.

[markyezy]

4 hours ago, kodiakdenali said:

There are a couple of places where you can get high beam activation signals. on the BCM there is a wire that gets ground when the high beams are on, this is what turns the relays on in the under hood electrical center.

module X5 (brown) pin 18, brown/violate: high beam relay control.

you could tap into this wire, run it through your switch and then through the firewall to one side of your relay coil. in this case the other side you would connect to 12V. whenever the switch is in the on position, high beam circuit will activate the relay and turn on the light bar.

another option is at the under hood electrical center itself. there are 2 fuses for the high beams (see the diagram in the manual or under the fuse box cover) the relay for the high beams is before the fuses, so the fuses have 12V only when the high beams are on. you could use an add a fuse type product (micro-ATC type) to get that signal, and use that to activate your relay. in this case though to have it switched you'd have to put the switch between this point and your relay, so you'd have to run 2 wires through the firewall. in this case the first option is actually easier.

either way you setup the relay to be activated the contact side of it would be the same, a suitable high current power source (fused) to one side of the normally open contact, and the other side to your light bar's positive wire.

 

wire size and fuse rating depends on how much current your lights draw (combined). This information should be in the documentation that came with them, or they might have come with fused wiring that would be a good indication as to the fuse capacity you need.

Thank you ! If I was to get a wire harness kit like this: https://www.amazon.com/dp/B06XZ2BSNQ/ref=cm_sw_r_cp_api_glc_fabc_Gh1dGb1798ZCH 

 

Would it be easiest to just use the wire under the dash to run to the switch and not have to change anything from the current kit? 
 

what wire would I replace on the switch with the one from under the dash? 
 

Also my lights appear to be 4.5A draw each, so if I have 4 of them I’m understanding this kit would be plenty? 
 

Thanks again! 

[2k19Sierra]

Pics of how you mounted the light bars? 

[kodiakdenali]

5 hours ago, markyezy said:

Thank you ! If I was to get a wire harness kit like this: https://www.amazon.com/dp/B06XZ2BSNQ/ref=cm_sw_r_cp_api_glc_fabc_Gh1dGb1798ZCH 

 

Would it be easiest to just use the wire under the dash to run to the switch and not have to change anything from the current kit? 
 

what wire would I replace on the switch with the one from under the dash? 
 

Also my lights appear to be 4.5A draw each, so if I have 4 of them I’m understanding this kit would be plenty? 
 

Thanks again! 

Thay harness should be ok with your lights. The problem with the wire under the dash is this harness, like most, is prewired for the switch to be switching 12v to the relay with the ground side of the relay being permanetly attached. The wire under the dash is a relay control wire which gets ground when the highs are on. You can use this harness, but you will have to rewire it. Honestly though if you are not familiar with wiring and hooking up relays im not sure i'd recommend you to try to do this yourself. I certainly dont mean to offend or anything, but wiring can be a fire danger if its not done right. Safety first! It's not that hard to do, but things can get a little complicated...

If you want to use this harness it would be easiest to connect it to the bigh beam fuse under the hood and just run the 2 wires through the firewall. In which case in the diagram below connect the small grey wire coming off the switch to the high beam with an add a fuse instead of to the battery like it shows. The small gray wire and the small blue wire need to go through the firewall. Thats the only difference. The big red wire still connects to the battery (or other suitable connection point, there are a few good candidates)

if you really want to connect it to the bcm wire then you need to rewire the harness. Relay coils are bidirectional. As long as there arent any unwanted internal connections in the harness...

The switch is wired for a constant ground (for the led indicator) and a constant 12v, when you flip the switch the output wire gets 12v. You should be able to rewire the switch so the output is ground when the switch is on. Simplest way is to swap the 12v and gnd wires where they connect to the switch. Issue is if the switch light is an led the switch would work, but the built in light may not.

If you do that and the switch then puts gnd on the blue wire when on just connect the other side of the relay coil to 12v instead of ground. In the diagram above that means the large grey wire from the relay, connect that to the red wire after the fuse. Just connect it right there at the relay itself. Next problem, the diagram doesnt make it clear, but i would bet the ground wire of the output on the far right is connected to the ground going into the relay.  You will need to cut that wire and connect it to ground separately. Or dont use that wire at all and ground your lights independently. But remember the relay side of it may have 12v on it at this point, so you must be careful to secure it where it cannot short on anything. It's honestly pretty simple, but hard to explain...

Yeah...i wouldn't do it that way unless you're confident with wiring and double check everything before you power it on. You dont want to fail the smoke test

[markyezy]

14 hours ago, kodiakdenali said:

Thay harness should be ok with your lights. The problem with the wire under the dash is this harness, like most, is prewired for the switch to be switching 12v to the relay with the ground side of the relay being permanetly attached. The wire under the dash is a relay control wire which gets ground when the highs are on. You can use this harness, but you will have to rewire it. Honestly though if you are not familiar with wiring and hooking up relays im not sure i'd recommend you to try to do this yourself. I certainly dont mean to offend or anything, but wiring can be a fire danger if its not done right. Safety first! It's not that hard to do, but things can get a little complicated...

If you want to use this harness it would be easiest to connect it to the bigh beam fuse under the hood and just run the 2 wires through the firewall. In which case in the diagram below connect the small grey wire coming off the switch to the high beam with an add a fuse instead of to the battery like it shows. The small gray wire and the small blue wire need to go through the firewall. Thats the only difference. The big red wire still connects to the battery (or other suitable connection point, there are a few good candidates)

if you really want to connect it to the bcm wire then you need to rewire the harness. Relay coils are bidirectional. As long as there arent any unwanted internal connections in the harness...

The switch is wired for a constant ground (for the led indicator) and a constant 12v, when you flip the switch the output wire gets 12v. You should be able to rewire the switch so the output is ground when the switch is on. Simplest way is to swap the 12v and gnd wires where they connect to the switch. Issue is if the switch light is an led the switch would work, but the built in light may not.

If you do that and the switch then puts gnd on the blue wire when on just connect the other side of the relay coil to 12v instead of ground. In the diagram above that means the large grey wire from the relay, connect that to the red wire after the fuse. Just connect it right there at the relay itself. Next problem, the diagram doesnt make it clear, but i would bet the ground wire of the output on the far right is connected to the ground going into the relay.  You will need to cut that wire and connect it to ground separately. Or dont use that wire at all and ground your lights independently. But remember the relay side of it may have 12v on it at this point, so you must be careful to secure it where it cannot short on anything. It's honestly pretty simple, but hard to explain...

Yeah...i wouldn't do it that way unless you're confident with wiring and double check everything before you power it on. You dont want to fail the smoke test

 

 

 

Thank you for this ..

 

Wouldn't it just be simplest if I take the wiring harness, run an extra wire from the bright light fuse to the switch and be done? 

 

Mark 

 

[kodiakdenali]

25 minutes ago, markyezy said:

 

 

Thank you for this ..

 

Wouldn't it just be simplest if I take the wiring harness, run an extra wire from the bright light fuse to the switch and be done? 

 

Mark 

 

yes! electrically that's the same approach as plan A above, that's how I'd do it. simplest way.

[markyezy]

13 minutes ago, kodiakdenali said:

yes! electrically that's the same approach as plan A above, that's how I'd do it. simplest way.

Awesome thats what I am going to do - I have 4 light bars and cant seem to find any harness with 4 leads so Ill likely just get two harness, wire them up that way with two switches and run two wires off the fuse into the cabin - what gauage should I run from the fuse? Any harm in running two wires off of one fuse tap? 

 

Just run a tap like this directly into the switch, would I still be able use the illumination part or is that what you're saying would need some re wiring of the harness? 

 

Again thanks for the help! 

 

Cheers

Mark

 

[slj2008]

Pics of your set up. Thanks

[kodiakdenali]

that should work fine! you shouldn't have any issues with the switch working, the harness was setup for it being a positive side switch and if you're running off the high beams fuse that's exactly what you have. the only difference is your power is on only when the high beams are on instead of all the time. as a bonus the light in your switch would also light up only when your light bars are actually on, so you can leave the switch in the on position 24/7 if you want to. it won't light up or drain the battery, but when the high beams come on if the switch is on the indicator will light up then.

 

the wire that comes off the high beam circuit only runs the light in the switch and the relay, very low current. to be safe you should run a wire that is capable of handling more current than whatever your fuse is rated for. 5A is about the smallest you can find easily. they do make 3A fuses in that size I'm pretty sure but you may have to search to find one, I'd run anything from 22awg to 18awg. I usually use 20 or 18 personally for almost everything that's low current, even if you could technically use something much smaller. its just easier to work with wire that isn't so tiny.

 

your lights combined should draw around 20A and it looks like the harness you are looking at should handle that just fine. if you're comfortable doing so you can splice the output wires and run all 4 lights off one harness, or  get 2 harnesses, there should be no problem with that at all. also gives you the flexibility to have your off road lights on 2 different stages, you can have 2 on, or all 4.

if you do that you could run just one wire from the fuse into the cabin, then split it and connect it to both switches, there's plenty of capacity in a 20awg to run 2 switches and 2 relay coils. that would save you some wire!

[Heloise Burgess]

Everything about electronics and wires is weak here, and I have always turned to more experienced people for help. I tried to install the LED bar on my car myself. I almost damaged all the wiring, so if you have no experience in this matter, it's best to contact the specialists. This is my advice to you. The only thing that I have been able to install recently is LED smart light bulbs in my house. Still, as you all understand, there is no difficulty installing a light bulb. Well, I hope my post will help you, at least somehow. I'm sorry that I didn't give an exact answer to your question, my friend.

Edited May 31, 2022 by Heloise Burgess