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Discussion Starter #1 (Edited)
The Electrical System ExplainedBy Gil "usmcdoc14"
[ PART 1 ] [ PART 2 ] [ PART 3 ]
Now let us get to the meat and potatoes, this is why you read all of this, right? Now you have the knowledge to add on accessories so you may as well use it.
The Stuff
I am now going to show you the basic, usually first upgrade done to any off-road vehicle.
Adding a set of lights with a relay... with a slight twist!
I am not using a 55w halogen as I have killed dozens of them, nor am I going to use HIDs as those don't survive me as well as I would have hoped either. Don't get me wrong, my HIDs fully rocked, but they had limitations (more on that in a bit). So I went with LEDs as the technology now offers a product that is incredible.
I will be showing my install using Dually D2 LED lights from Rigid Industries. Rigid Industries - LED Lighting | Rigid Industries
A small, sorry, almost TINY light at 3x3 inches the D2 is the regular Rigid Dually turned to 11. Producing over 2600 lumens it is ridiculously bright for ANY size much less the tiny footprint it occupies. And with that bright light it does not come with the usual downside of high amps, they draw only 28w of power, that's less than 3 amps! They are also VERY hard to kill as LEDs have no filament, no outside electrodes or pretty much anything that can die by vibration or impact. Rigid has video of their LEDs online being dragged, run over and even shot while still working. Internally they are protected from the one thing that does kill LEDs, heat. With temperature sensing circuitry, the light unit will regulate between 80-100% power to prevent damage and keep the LED optimized for the environmental conditions. With no airflow the temperature sensors will automatically dim the light roughly 10% keeping you from cooking it.
But enough on that for now, lets show you how to wire them.
Rigid Industries includes a very well made quality harness with their LEDs that should work for 99% of the people installing their lights. I mean this harness makes every other lighting system I have purchased look like a fire hazard.
But I am the 1% who it will not work for as I have another project later that covers why a little later. But, because of this I will show you how to wire in a relay switched lighting system.
First problem we run into is the Jeep JK CANBUS electrical system. Most if not all of the JK wiring uses a pulsed system to determine issues such as a blown headlight. In simple terms: The computer measures the Ohms and Amps and if the numbers don't match it throws a code or does weird things when you add stuff. Like when you add LED tail lights or why HID headlight upgrades flicker. Avoid the factory wiring at all costs, it will save you lots of hassle in the long run.
Constant power is easy, hook a fused wire direct from the battery. Switched or ignition on power is a little more complicated, but still easy.
The one for certain switched power source is the cigarette lighter. It also will have no issues because its also made for a variable amp draw and is not pulsed because that would cause issues with accessories that use a lighter plug. But ONLY use this wire to be a switching power to a relay! Don't use it to power a bunch of things.
Now I pulled apart my dash and tapped directly into the wire and I would recommend the same. But there is a reasonably safe alternative and that is to use a fuse tap in one of the few ways I recommend.
Once again, you are ONLY using this as a switching power! Nothing more than that, so it is not at risk of being over drawn on its amp rating. Look for the cigarette/acc port fuse in your fuse block.
Install the tap and re-install the fuse.
I did not fully seat anything because this was just a demo, but you can see where it goes. Now test this power with a multi-meter or a test light and make sure it is only powered when the key is in the "run" position in your ignition. Run your wire back into the passenger compartment and you can start. There are all sorts of holes in the firewall that you can route the wire through or drill a new one. Just always install a grommet in a new drilled hole to keep the wire from becoming chaffed and shorting out.
I digress, lets get back to why you are reading this.
Here is your relay, use a relay plug instead of blade connectors, don't be a hack.
Some relays are marked on the top as to the wiring but here is a go-by if you flip the relay over and just look at the numbers underneath.
30 = fused power from the battery
87 (and sometimes there is a 2nd pole labeled 87a) = lights or whatever you want to power.
This is the circuit that is completed when power is applied to:
85 = positive used to close the relay
86 = ground
So I solder the wire from 87 to the positive wire for the Rigid D2s, then I run 30 to the battery with a fuse right near the battery (no fuse in it yet). Both the 86 wire and the D2's get their own nice solid ground with a ring terminal. I install the fuse and then touch the 85 wire to the battery and the lights should (and did) come on. This is just a test to make sure everything is working right before I wire everything in place. Remove the fuse and then run your switch wire (85) to whatever you plan on using as a switch. Whether it be a "normal" single throw switch or a self illuminated one is your call. Test your lights and then mount them up.
And yes, it is that simple.
What happens when you have a lot of accessories? It's the same problem I had, you run out of room for switches. Switches on the center counsel, switches on a custom dash panel, switches next to the steering wheel, you get the idea. Scattered all around and a LOT of wire. So I decided to go with a custom switching system and I wanted the smallest space taken up on my dash. So I went with a switch panel from Wired HDH: http://www.wiredhdh.com/
Being flexible and no thicker than a credit card with a very small foot print for the control panel it allows a lot of mounting options. You mount the tiny panel where you need the switches and the control module under the dash or hood. This is pretty much the smallest way you can mount 8 switches in one spot!
If you have not figured by now your Jeep has a removable roof. I hope this is not a surprise to you. When summer comes I take off my top and once in a while it gets rained into. The Wired HDH panel does not care if it gets wet, or if you spill soda on it if you mount it on your center counsel by the cup holders. You will not whack your knee on it if you mount it next to the steering wheel or breaking off a toggle if you hit it. Each button is rated for a million presses so it is not going to wear out its contacts. It is complete with all wiring except for the ones you run to your accessories and they include the most ridiculously extensive label kit that covers just about everything you will ever install in your Jeep.
One of the most kick ass features is that the buttons are fully programmable. You want the switch to be a momentary switch like for a winch? Done. You want it only on when the ignition is on? Done. So when you change your accessories the same controller will work for everything and you do not have to add more holes.
You mount the switch panel ANYWHERE you want and mount the control module under the dash or under the hood. I drilled a hole through my firewall and mounted the control module on top of the factory fuse box.
This way no more wires have to be run inside the passenger compartment and I can keep the wires much shorter and more organized.
Now as for the switch panel? I did a little custom work and mounted it on the dash.
Now there is nothing in the way of anything. When I cage the jeep there is nothing sticking up high to get in the way of the tube. It falls naturally at my right hand and is centrally located. You just insert your "85" wire into the corresponding numbered slot in the control module, wire the rest of the relay as normal and the system now controls it.
End result of the wiring?
Here is the Rigid D2s vrs the factory fog lamps, its almost an embarrassing set of pictures.
Factory: D2FACTORY.jpg
Rigid D2 D2ON.jpg
Time for a new front bumper as I see no need for the factory fog lights at all. These put every 55w halogen I have ever owned to shame.
LED's are very impressive, to the point I have upgraded most of my lighting to them. For the low amp draw and durability I feel they are more than worth it. Read here for more on the Rigid Industries LED lights as I compare them to a 5 light 35w HID bar that was replaced with a Rigid E series 50" light bar. The results more than speak for themselves.
Rigid 50" LED bar vrs. 5 35w HID bar
More powerWiring high amp items is where all the lessons you learned in this article come into play. Because this is where you have to do things correctly and not half-ass it, if you don't things will not have enough power or worse.
High amp items must be run off a relay as the switch required to handle the amperage would either be too big or bulky to be used comfortably in a passenger compartment. You also need to run the correct gauge wire for the correct length or you will end up with either a cooked wire or a voltage drop that will cause issues with the accessory.
Yes, unless the wire is big enough you can actually drop the voltage enough to cause problems with accessories that are voltage sensitive like inverters.
Anyway, you have to correctly fuse or circuit protect the accessory because some high amp items will have a higher amp startup than what a normal fuse can handle. This requires you to run a slower acting fuse or a circuit breaker. You have to use proper connections and grounds so that these do not become your weak link.
Our high amp accessory is a Viair 400C compressor and mounting from Dominion Off-road. Dominion OffRoad Hardcore Jeep JK Accessories
Dominion's packaging and mounting system made it a no brainer to get it from them. The mounting bracket places the Viar compressor in the unused space next to the brake master cylinder. They also offer a full package with a tank and mount, I have the space there already used so my tank is in another location.
Running an on board air system is an invaluable tool, from airing back up after a trail or fixing a flat. The Viair 400C is puts out 2.54 CFM flow and can hit 150PSI, it will definitely fill your vehicle needs. Features include a standard 1/4" NPT stainless steel braided leader hose with inline check valve and is thermally protected.
Yes CO2 is a great option but once you run out of CO2, you are out. The Viair will keep giving you air as long as you have power to it.
This is a great location for mounting the 400C as it is pretty much useless space otherwise.
The rest of the mounting for the 400C and Dominion's air manifold and bracket were simple and straightforward.
So lets get onto the wiring shall we?
The Viair 400C needs 2 kinds of switching, one for power and one for when the PSI in the tank drops and needs to be replenished. The first will be handled by a traditional switch to relay (or in my case the Wired HDH to a relay) and the 2nd with a Viair pressure switch. The specifications for the compressor are not only listed in the literature but clearly printed on the side of it.
So I know that I need to handle 30 amps. If I was choosing wire I would use this as my basis plus the length I need to run the wire. I also need to make sure my fusing is rated to the compressor and UNDER the failure amp of the wire.
But luckily the included kit from Dominion covers these things perfectly. In Fact they include everything you need including switch and internal pressure gauge.
I ran a fused (30a) power directly from my battery to the relay (rated at enough amperage) to the positive wire of the 400C. Grounded the relay and than plugged the switching wire into my Wired HDH (or a normal included switch should you choose) It is exactly the same as we wired the lights above. Where we get different is the pressure switch to cycle the compressor. First thing first is to make sure it can handle the amperage or will it need its own relay. Viair makes all their components compatible and you can se it is clearly marked on the said that it can handle the power requirements.
This gets wired in line between the ground wire of the 400C and then I made sure there was a solid clean ground for it to attach to.
So now the sequence of events that happens is:
I press the switch to turn on the compressor.
This powers the relay and it completes its circuit.
Power now transmits to the compressor.
The pressure switch when below a set PSI completes its circuit and the compressor is grounded and starts running.
When the OBA system reaches its set PSI the pressure switch opens the circuit and the compressor stops
Or I turn off the switch that turns off the relay, opening its contacts and power stops going to the compressor.
You see its not that hard, none of this is. When you go and break it down to easy to understand terms it clears it up. Now that you are informed and educated to safely wire your accessories you should go out and do it! Here is a thread on Pirate4x4 that once you feel comfortable wiring is full of helpful tips and advice on how to keep your wiring safe and clean. Post your Wiring tricks - Pirate4x4.Com : 4x4 and Off-Road Forum
Your accessories cost a lot of money and your JK even more. This is not the place to skimp on details or be hack on your installation. I hope you learned some valuable lessons here and now you don't fear putting new toys in your Jeep.
At first automotive wiring intimidated me, more so than rebuilding an engine. But once I started to break it down into easy to understand terms I have no fear of wiring anything into my JK.
And after a hard day of wiring up your Jeep you get the satisfaction of going from this in the daylight. DONE.JPG
To this finished result where you no longer fear wiring, or the night. ALLONNIGHT.jpg
Please visit our forums as our vendors carry the products shown in this article and much more. And for any questions you may have as there is always a helpful person to assist you with your JK no matter what it may be.
- Doc14

Odyssey Baterieshttp://www.odysseybattery.com/
EnerSys Energy Products Inc.
617 North Ridgeview Drive
Warrensburg, MO 64093-9301 USA
Tel: 1.660.429.2165
Rigid Industrieshttp://www.rigidindustries.com/
2630 N Ogden Road Suite 101
Mesa, AZ. 85215
Phone: 480.655.0100
Email: [emailprotected]
Wired HDHhttp://www.wiredhdh.com/
3466 E. County Rd. 20C Unit B9
Loveland, CO 80537
Phone: (970) 292-8542
Fax: (970) 292-8621
Toll Free: 1-800-461-3414
Dominion Offroadhttp://dominionoffroad.com/
Phone: (626)Trails1
15 Edelman
Irvine, CA 92618
Ph. 949-585-0011
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