Switching Reverse/Rear Lighting

bobholthaus

Observer
I am mounting Rigid Duallys in my rear bumper. I plan to have them on a 3-way switch to run them independently of my reverse lights. But, I also have LED reverse lights on all three of my trailers. Is there a way, without hacking into a bunch of wiring, to actually tap the reverse light circuit of the JKU to make the trailer reverse lights go on as well? Ideally I'd be tapping a wire somewhere up under the dash. I realize that I'd probably have to use some the device inline that only allows power to flow one direction (solenoid? Having one of those brain freeze moments here) so that my power doesn't backflow into the canbus system. Thoughts anyone? I also want to do this exact thing with my dome lights if someone knows where to tap those too. Thanks.
 

BuckeyeBullet

Observer
The device that only allows current flow in one direction is a diode. All LEDs are diodes, they just happen to emit light, too ;-). Not sure if you'll need any others, I've never worked on anything with a canbus system.

My choice would be to tap into the reverse light circuit for the trailer at the vehicle reverse lights. With all LEDs, current draw should not be an issue for the factory wiring size.
 

just eric

Adventurer
Why not add a sPOD or other variant and run them all to a switch? Makes things very clean and maintains the integrity of the vehicle wiring. Just a thought.
 

bobholthaus

Observer
Gentlemen- thanks for the replies. Yes, diode is what was thinking of. I am using a Rugged Ridge Switch Pod on the A pillar. I was really wanting to know if there was somewhere to tap the reverse wires up under the dash so that I could control the oem reverse lights, my new rigid lights that will be tied into the oem, and the trailer reverse lights, all at the same time on bith sides by tapping a single wire. I can tap all three in the back, but then I have to run wiring all the way to the front. If I could tap a single wire somewhere under the dash, that would be much simpler. The diode would be used "in front" of my tap so that the power wouldn't back flow into the canbus system of the JK; I've read that that system is super sensitive, so I wouldn't want to jeopardize it. I know where to find all the wires I need in back, there's just a bunch more work to do. I was looking for a short cut, as I know all wires in back eventually run up to the front. Maybe in the TIPM there's a single circuit for reverse lighting that I could find. Thanks.
 

Rynomar

Observer
Backup Diagram.JPGView attachment 128592I hooked the reverse light circuit up to a relay to activate my dually's and then tied the relay power into a main feed going from a switch up front directly to the reverse lights. This way, they kick on anytime I put it in reverse, or when I hit the switch. Here is a diagram of what I did, works great.
 

JIMBO

Expedition Leader
:sombrero: I'm tired of adding wires to off-road vehicles, so I just gotta sPOD-



6-switchs/w "Source" control box and everything sealed/w aircraft conns/harness/sw's--

I've got CB/Auto fluid temp/OBA/rear lites/driving lites/windshield lites-

Immediate access-

:costumed-smiley-007:wings: JIMBO
 

bobholthaus

Observer
Rynomar- that's very close to what I'm talking about, but I also want my reverse lights on my trailer, the ones that run through the factory wiring, to light up as well. I guess I need to just splice that harness up behind the taillight (my trailer wiring harness is the Mopar plug and play unit). Two questions: how do you choose your diode size and does anyone make a diode that is waterproof with wires on the end, so I can splice it inline using waterproof heat shrink butt connectors? (I've found that the ones made by Molex are bombproof). I'm talking about actual covered wires that are flexible, not something that needs to be soldered and covered with electrical tape. I want a completely sealed system for longevity.
 

Rynomar

Observer
I would rig up the relay in the area behind the drivers taillight to have it in the same spot with your trailer plug and play harness. Are you using a 7 pin trailer harness or a 4 pin? If it is a 7 pin, the center pin should be for your reverse circuit. If you have a 7 pin and your trailers are all set up with 7 pin harnesses, you will just need to tie your trailer LED's into the trailer wiring to get them to light up. If you have 4 pin harnesses, I would consider upgrading to the 7 pin as it is going to get pretty involved wiring the LED's otherwise. That will also give you the cleanest finished product, but make for a good bit of work with three trailers.

You could run a power line from the relay to the trailer LED's, but you would then need to use some sort of quick connector like a delhpi maybe to connect it along with the 4 pin harness. For a ground, you could either connect into the ground off of the 4 pin harness or run another one along with the reverse circuit.

For diodes, you will need to figure out how many amps your lights are going to be drawing. I like to add 50% to that for a safety margin. As for sealing them, I use quality waterproof heat shrink tubing from DelCity and solder the diodes in to the wiring. That will give you a totally waterproof seal.
 

bobholthaus

Observer
I use 7 pin on all trailers, to have the reverse and constant 12v. That's what I was thinking, to tap it all behind driver taillight. Where do you buy your diodes? Thanks for the responses, I truly appreciate it.
 

Rynomar

Observer
Cool, it should not be too tough getting the LED's rigged up then. I usually just get my diodes from Radio Shack. I am sure there is a good spot to get them online, but Radio Shack is just down the road! Good luck!
 

bobholthaus

Observer
Okay, I'm at Radio Shack. Their 3A diodes are 50v, 200v, or 400v. The only 12v diode here is a 21mA which is way too small. They also have 1A at 50v, 200v, 400v and 600v. And they have no 6A at this location. Are any of these what I need to buy? Thanks guys.
 

Rynomar

Observer
These are the ones that I have used with success. Depending on the size you need,
1A - Part Number 1N4004
3A - Part number 276-1141
6A - Part Number 276-1661
 

ThirstyCamel

New member
The rear lighting wiring harness runs to the front and is easily accessable in the passenger footwell. You can pull one of your tail lights and get the color coding for the reverse light from there and then just find it in the bundle up front in the passenger footwell. You'll want to use a relay to power your additional lights. I would probably use a double pole relay to make it easy. You'll need a diode and a capacitor; the diode to prevent back feed into the CANBUS and the capacitor to keep the relay from chattering due to the CANBUS wave. You'll need to jumper the capacitor across the + & - terminals of the relay (switching side) and put the diode inline with the feed signal (also switching side). Because all you're doing is energizing the relay you don't need much of a diode (1 amp should be more than enough) or capacitor. I've got the radio Shack part numbers tucked away somewhere but I'm at work right now and can't lay my hands on them. You can try PMing dsy (member of this board) and asking him for the part numbers. I actually took his advice on the part numbers and they worked out great (been working for over 2 years now).
 

bobholthaus

Observer
Gentlemen, great response. See below diagram, which is rough, but accomplishes what I'm trying to do. In this setup, when I flip my 3-way switch to constant, the intent is the Rigid Lights to go on (marked "R" on the diagram) and the trailer reverse lights (marked "TR"), but not the OEM reverse lights (as they are not LED - they're marked "OEM"). When the swich is flipped over to the "switched" side, all three sets of lights will go on when I put the JK in reverse. ThirstyCamel, would the capacitor go across the 86-85 part of the relay? What size relay do I need downstream of the OEM reverse lights, where my Rigid lights are tied into the factory trailer reverse lighting (where I have the "?" in the diagram)? Am I looking at this properly? Thanks!
 

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