Help with Back-Up Lights

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I had thoughts of adding additional reverse lighting in the future, so when installed my trailer hitch wiring, I soldered on a lead to the pigtail/extension on the trailer wiring harness's reverse light wire. The trailer hitch wiring has a converter box which already has 12V running to it, so adding a relay to power additional reverse lighting would be easy peasy.

After reading the posts here...I'm a little confused whether the CAN-BUS is going to let me do this. The only additional load on the stock reverse lead would be that of the coil in the relay. Is that enough to upset the C.B.?
I wish I could tell you, it sounds like it should work. Just give it a try.
I’m glad I had to wired with a switch. That way I can control when I want the lights on.





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Bingy

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Wired my cube lights directly to the trailer harness back up reverse wire (white wire with orange trace). Then ground wire to same harness black ground wire. Everything works fine. Comes on in reverse, goes off when not. I have full LED lights all around.

phone pics 702_LI.jpg
 
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Did you ever find out the answer to this?
No not really, but it did work out for the best. I ended up wiring them to a switch so I can control when I want them on.
 

WillDo559

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No not really, but it did work out for the best. I ended up wiring them to a switch so I can control when I want them on.
I eventually want the auxiliary switches, but for now I tapped into the tail lights. Just figured it out, the right side was purple/white and the left was brown/white. I needed some light for the backup camera.
 
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Shenanigans

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Using a standard relay, wire pins:
86 is the trigger, i.e. a pigtail attached to the factory reverse tail-light wire.
85 ground to chassis
30 12V fused source from battery
87 to load, i.e. the rear back-up aux lights

I would think the amperage to "switch on" the relay should be minimal.

If this does not work... I suspect you can use the wire coming off the transmission to trigger the relay to power the lights. That being said... I am not that familiar with the wiring coming from the JL transmission to the vehicle to "trigger" the factory lights. Older transmissions had a reverse switch that was easy to tie/splice into.

Most expensive option, if you do not have the AUX power group already installed, is to install the MOPAR switch bank. However, you will need to manually switch the input to turn the lights on whilst attempting to reverse.

EDIT: The MOPAR switch bank may be more desirable. You may want to turn on the rear bumper lights to illuminate something behind you while keeping the transmission in [P]ark or [N]eutral for an AT or neutral for a MT.

Driving_light_relay_wiring_diagram.png
As a mecp certified 12 volt geek, this is 100% correct.
 

SONofHELGI

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Something that sounds technical, but it's not.
I did this and it worked perfectly on mine. I wired everything under the left rear plastic shroud which conveniently offered a grommet to run the wire out to the lights, a grounding point and 12V source to power them. I did install the switch, so instead of the 87 leading straight to the backup lights. It is spliced to the switch and the backup lights. This way if I need lights in the back I just flip the switch, but when I'm driving and I put it in reverse, the lights come on as well. Just FYI, from the light taillight wiring harness, it's the white wire with light brown/tan stripe. I'll do up a wiring diagram in a little bit and post it along with pictures.
 

SONofHELGI

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Something that sounds technical, but it's not.
I hope this helps. I should have taken pictures during the install but I was focused on what I was doing. If I find someone local who wants to do the same thing, I'll do a complete write-up and take pictures.

With this setup, when I put it in reverse, the reverse lights and the external lights come on. If I flip the switch, the left reverse light (the one I spliced it into) and the external lights come on.

Removing the rear panel to do the install wasn't very difficult, there's a youtube video showing how to do it when a guy was prepping the vehicle for internal rhino-lining.

Reverse Lights.jpg
 

robaw

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I hope this helps. I should have taken pictures during the install but I was focused on what I was doing. If I find someone local who wants to do the same thing, I'll do a complete write-up and take pictures.

With this setup, when I put it in reverse, the reverse lights and the external lights come on. If I flip the switch, the left reverse light (the one I spliced it into) and the external lights come on.

Removing the rear panel to do the install wasn't very difficult, there's a youtube video showing how to do it when a guy was prepping the vehicle for internal rhino-lining.

Reverse Lights.jpg
Nice diagram. FWIW - if you add a diode between the reverse cable wire and the relay, the left reverse light wouldn't come on when you use the switch.
 

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Nice diagram. FWIW - if you add a diode between the reverse cable wire and the relay, the left reverse light wouldn't come on when you use the switch.
This is exactly what I want to do. Can you show me a pic or link of a diode that I should use? Should I just grab a one way diode off amazon? Thank you for your help.
 

robaw

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This is exactly what I want to do. Can you show me a pic or link of a diode that I should use? Should I just grab a one way diode off amazon? Thank you for your help.
Nothing fancy needed, you can get them at electronics stores (like Radio Shack) or of course Amazon. For this sort of thing I usually use a 1N4001.
 

Rhinebeck01

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@Kingpre
@robaw

Agreed, often "fancy" is not needed.. but sometimes a more stout lets say diode might be more appropriate for certain type of installs.

Personally, I would not use a pretty frail, diode like the 1N4001 for an exterior install under a Wrangler for example. Of course, I am a worst case scenario kinda guy so..

Sure, I would use the 1N4001 on an interior install..

Also, diodes like the 1N4001 need to be soldered in. Not all guys/gals are wanting to solder and would prefer quick connects.

For sure, diodes like the 1N4001 are way cheap....
 

DocJLU

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Wired my cube lights directly to the trailer harness back up reverse wire (white wire with orange trace). Then ground wire to same harness black ground wire. Everything works fine. Comes on in reverse, goes off when not. I have full LED lights all around.

phone pics 702_LI.jpg
This is the same way I wired both of my cube lights and I did not have any issues.

This is exactly what I want to do. Can you show me a pic or link of a diode that I should use? Should I just grab a one way diode off amazon? Thank you for your help.
I used Roadmaster 792 Hy-Power Diode, (Pack of 2) https://www.amazon.com/dp/B0002UHVHI/ref=cm_sw_r_cp_tai_zsZpCbCHDPYD6 and wired it into my auxiliary switches next to the battery (along with my rock lights). They turn on in reverse and when I switch them on.
 

chillipepr1

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@Kingpre
@robaw

Agreed, often "fancy" is not needed.. but sometimes a more stout lets say diode might be more appropriate for certain type of installs.

Personally, I would not use a pretty frail, diode like the 1N4001 for an exterior install under a Wrangler for example. Of course, I am a worst case scenario kinda guy so..

Sure, I would use the 1N4001 on an interior install..

Also, diodes like the 1N4001 need to be soldered in. Not all guys/gals are wanting to solder and would prefer quick connects.

For sure, diodes like the 1N4001 are way cheap....
Just curious what lights you used in your install??
 

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