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How can I wire this up?


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I'm wanting to add some additional light on the back of my 2023 2500 AT4. So, I've purchased a CURT (56584) 7way T with a 5way plug as well a set of Rough Country 6" slim light bars (97026B) for a side by side.

 

My thoughts were to add the 7way T so I didn't have to cut or tap into any factory wires and then wire the lights to the 5way reverse wire.

 

But after getting the lights from Rough Country today, I'm a bit confused on how I can do this. The light bars come with a wiring harness that includes a relay, two wires plugs for each light, a battery +/- leads and a on/off switch (which I don't want since I don't want to turn them on/off by switch but when the truck is in reverse).

 

Any suggestions on how I could make this work?

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Use your 7way tee.

 

Use the 7way 12volt+ to the relay 30.

 

Light bar 12+ to relay 87

 

7way 12- and light bar 12- to relay 85.

 

Use 7way reverse (to trigger light bar ON) to relay 86.

 

ETA... throw light bar ON/OFF switch into pile.

Edited by gemarsh
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What @gemarsh says.

If you didnt want to tie up your 7 way you could always run a 12v + fused line from under the hood to the area behind one of the tail lights and make your relay connections there. If you mount the relay there and keep it high it should stay well enough out of the slop assuming its a decent relay. Split loom and zip ties are your friend. I would also use some dielectric grease on the relay connections. 

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You will have to tap the 7way wires between the male/female plugs.

 

Cut off the 5way plug off and cut the brown off the 7way, and tap that brown wire to the 7way black(12+).

 

The white wire will be ground (12-) so leave that attached to the 7way. 

 

The blue wire should be REVERSE trigger, so leave that attached.

 

The green and yellow wire can be cut off the 7way.

 

Seal your cuts on the 7way.

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14 hours ago, sage55 said:

 

 

@64BAwagon what do you mean this will tie up the 7way? Will I now be able to use it for my trailer?

I wasnt familiar with that adapter setup, my comment was generic in that the method I suggested leaves your stock 7 way unmodified. 

You would then connect your 12v+ line to 30 on the relay

85 to an existing backup light wire ( a signal to turn on the lights, doesnt pull enough power from the OEM system to cause an issue) 

86 to ground 

87 to your 12v+ on the new lights. 

Ground the new lights to the chassis wherever you like. 

Edited by 64BAwagon
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15 hours ago, Pryme said:

I formally appoint Gemarsh as the resident electrician. Man I didn’t understand any of that. I used to wire up amps in my vehicle but this sounds way more complicated. 

I'll second that!

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On 11/27/2023 at 7:59 AM, 64BAwagon said:

I wasnt familiar with that adapter setup, my comment was generic in that the method I suggested leaves your stock 7 way unmodified. 

You would then connect your 12v+ line to 30 on the relay

85 to an existing backup light wire ( a signal to turn on the lights, doesnt pull enough power from the OEM system to cause an issue) 

86 to ground 

87 to your 12v+ on the new lights. 

Ground the new lights to the chassis wherever you like. 

 

I apologize, but I think I might be more confused now.

 

PXL_20231127_215329378-Copy.thumb.jpg.1bb72ec08bd41eaead23b49a27a853f4.jpg

 

The above is a picture of the harness that came with the lights. The wires to the left are battery positive and negative. The  two sets of wires to the right are connections for the lights themselves, and the bundle of wires in the middle is the switch.

 

Below is the Curt T harness. The wires going down are the 5 way connector.

 

PXL_20231127_215358261-Copy.thumb.jpg.f60b75d0dbe879c98945641be54a8415.jpg

 

How would you suggest hooking this up?

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Pull the connector from the bottom of the relay.

In very small print there will be a number next to each tab. Those correspond to the number I mentioned in my post. 

The wire for the "switch" is the one you will need to connect to the "85" as I outlined. You wont use a switch since your using the energized existing backup circuit to turn the relay power on. 

The black wire ring terminal should be "86" To make it even more confusing the 85 and 86 are interchangeable so it may be either way just swap them. 

The 2 power wires to the trailer come from the 87 terminal and go to your lights for 12v+

The red ring terminal should go to "30" on the relay and this is your power to the relay. 

The function of the relay is simply a remote switch that is triggered by power of some form being applied to the "85" terminal. It can be from another circuit or it could come from a manual switch. You mentioned you wanted it to come on with the existing backup lights. 

 

Your T connector is a whole other issue. You need to determine "IF" that 5 way is tapping into your backup light circuit AND the 12v+ at the trailer plug. Once you determine thats true then you will connect the backup light wire to the 85 wire on the relay and 12v+ will go to the 30 on the relay. Make sure to use the fuse somewhere in that line. NOTE THAT THE DIAGRAM I SEE DOES NOT SHOW A 12V+ COMING FROM USING THIS T ADAPTER. LACKING THAT CIRCUIT YOU WOULD HAVE TO CUT INTO THAT WIRE BETWEEN THE 2 ROUND CONNECTORS. IT IS DOABLE BUT NOT OPTIMAL. This is why I advocated for running a circuit from the battery to the area behind one of the tail lights and then place your relay there. 

 

I have done this type of setup on dozens of trucks and I dont use a T like the Curt unit you bought. https://www.curtmfg.com/part/56584  I dont see any diagram for the 5 way flat on the Curt site but you will want to make your connections on that end by cutting off the 5 flat plug. https://www.curtmfg.com/towing-electrical-wiring#:~:text=5-pin trailer wiring is,in a 5-way plug. 

You could according to the diagram connect the white wire on your new T to the ground on your relay 86 rather than using the ring terminal. 

 

You will need some zip ties, some split loom and some heat shrink butt splices to make your connections. Do not use anything other than heat shrink splices or you will live to regret it. The connections will be pretty easy but tidying up that monkey fist of wires will be a challenge. 

 

Scott

 BTW I have a LED marker bar with backup lights in it between the bumper and the hitch on my 3500. Since it was only a dozen or so clear LED I tapped the circuit behind the left tail light and pulled the power form there for the marker lights and the backup/clear lights. 

Edited by 64BAwagon
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Mine  The clear lights arent on but they are between the red LED's in this bar. I tapped all my wires behind the left tail light. Not enough power consumption to need a relay though. 

 

20230117_154758.jpg

20231129_082603.jpg

Edited by 64BAwagon
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2 hours ago, Pryme said:

Looks like a bunch of Korean writing or something haha. Yes add him. Seal of approval 

 

그것은 단지 단어일 뿐이며, 언어를 이해하는 사람은 없습니다.

  • Haha 2
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Words and knowledge and typing, sucks.

 

Here is a picture to help.

 

7187e2bcdb85d5f29eb9b03c1f03e7b7.jpg.dc01338776471b0729f98bad40564cc9.jpg

 

Pin 87 will go to your lights. Looks like it is already made up.

 

You grounds are already made up. Needs to be on 85.  Just ground your black ring terminal. 

 

Your red ring terminal needs to go to 12+. Whether it be in your 7way tee black wire or fuse box/battery, as 64ABwagon suggests. The other end needs to go to pin 30.

 

The blue wire needs to go the pin 86 and the other end needs to go to the reverse wire on your 7way tee

 

2 things, curt doesn't follow color codes that I understand.

 

1. Does one of the white wires have a black strip? That would be 12+.

 

2. You need to hook up the blue wire from the relay to the center pin wire on the tee, if there is one. If not you will need a test light to find the reverse wire.

 

Cut the switch wiring out of the picture and throw it on the scrap pile, except the blue wire. You will want that for your trigger.

 

Or return the curt tee and do as 64ABwagon suggests and tie into a tailight.

 

Your close, if he or I was there in person, you would understand. 

 

I would first see if anything on the 7way bumper plug lights up, with a test light, besides the 12+. I am remembering something about if these new trucks don't sense a trailer hooked up, the trailer module doesn't send power back there.

 

In that case I'm going to bail out and hopefully let 64ABwagon guide you through the tail light process, so it will be easier to understand, than listening to, 2 different keyboard people. 

 

 

 

 

 

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