Mojave front locker using Rubicon switch.

[Temperance]

The Mojave is the perfect vehicle for what I use it for: daily driver, towing, off road exploring, and overlanding (off-road camping). The only downside to the Mojave over the Rubicon for me is the lack of a front differential locker. Having a little OCD I like everything to look and function like it came from the factory. This led me down the path of how to add a front locker using the Rubicon off road console switch. It's actually much simpler than I anticipated, but it did require a fair amount of research.



Essentially you only have to install the Rubicon off road console and a short section of wire. The off road switch is what puts the front locker message on the can bus. The drive train control module is the same for all of the models and knows how to interpret the front locker message. Installing the off road console switch is just a matter or removing the Mojave one and installing the Rubicon version. Next you'll need to add the front locker wiring.



The plug (XY290A) you'll tap into is below the brake booster/master cylinder. I had to remove the driver side front fender to get access to this plug. This plug will probably only have the front driver wheel speed sensor wires coming from it. You'll need to run 4 wires from this plug to the front differential: fused ignition output, locker sensor return, front locker switch sense, and front locker return. These wires should be 18 gauge (spec calls for 20 gauge) and wrapped to prevent wear. You'll also want to wrap the section close to the exhaust with reflective tape. I attached the PDF files for the two plugs: XY290A and the front differential plug.

If you plan on using an ARB locker Z-Automotive sells a kit that can be used. You'll also need to enable the front locker. I used Z-Automotive Tazer mini for this. If you enable the front locker without a locker fix (Z-Automotive or other) or Rubicon axle with a hall sensor then you'll see a warning icon on the dash.



Parts List:

68359089AA Off Road Switch

1-1456426-6 TE Connectivity 4P Connector

1670146-3 TE Connectivity 1.2 F Terminal qty 8+

2138898-1 TE Connectivity Wire Seal qty 8+

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[Cmhaei]

Awesome! I was looking for someone to do this! I am in the same boat with making everything look factory. I hate a having aftermarket switches mounted. Thanks for the info!

 

[Temperance]

This is a follow up to my original post. The factory locker switch uses a hall sensor to detect if there is a magnetic field present at the axle. This can't tell if the locker is actually engaged. But it can detect if there is no power to the coil. I wanted this same functionality for the ARB locker. This can be accomplished using a common air compressor pressure switch at the axle; that and a custom electronic module.

The electronic module serves a few purposes. It reacts to the ground switching front lock input and utilizes a relay to turn on power to the ARB solenoid as well as the ARB air pump. The power to the pump is diode protected so that the locker doesn't engage when you manually turn on the pump to air up tires.

The second purpose is to mimic the hall sensor with the pressure sensor. The hall sensor in the factory lockers work in two wire mode. The hall sensor creates resistance according to the strength of the magnetic field. The drive train module provides a 6.5v signal and measures the current flowing through the circuit. A second relay, which is negative switched by the pressure sensor, switches between two sets of resisters depending on whether there is air pressure at the front axle.

I mounted the components on a small prototype board and put into a small water tight box. This box is mounted on a bracket above the brake master cylinder. The module itself uses only the 4 wire front axle plug and a ground as input. The output are two wires routed to the pressure sensor on the front axle and three wires routed to the air pump and locker solenoid.

I have attached an image of the Fritzing schematic as well as the schematic itself. The wire colors are as follow:

Input:
black -> ground
red -> ignition voltage
green - locker feedback
white -> sensor signal
blue -> sensor feedback

Output:
black -> pressure sensor ground
gray -> pressure sensor feedback
black -> solenoid ground
yellow -> solenoid voltage
purple -> air pump voltage (to switch that controls the relay)

 

[Temperance]

If anyone is interested in doing this (and does not want to hassle with creating prototype components) a fully engineered and tested air locker control module can be purchased here: https://temperance-ors.com

 

[JeepJunkie]

Wow, thanks for this.

 

[mdyucca]

Good info. I have a non rubicon and have been keeping an I out for take off axles. If I am able to get the axles this will come in handy. Thanks

 

[Temperance]

Good info. I have a non rubicon and have been keeping an I out for take off axles. If I am able to get the axles this will come in handy. Thanks

It may only work with Rubicon and Mojave models because they are both wired for the off-road switch. You'll have to figure out if the off-road switch plug is on the wiring harness or if it can be added.

 

[mdyucca]

Thanks for the heads up. I have the VOSwitch and it will be different than the Mopar Aux switches.

 

[outdoor.adventures]

Hi @Temperance, this is awesome and I appreciate the writeup. I have a Mojave and I plan to get an ARB air locker. I plan on buying the Rubicon front+rear locker switch - using your wiring products, will I need to only buy the Air Locker Control, or both the $160 Air Locker Control and the $70 Front Locker Wiring Harness?

Thanks!

 

[Beemer533]

This is definetely something I want to do, thanks for putting this together. Will your locker wiring harness work with the Eaton E locker or is just for the factory Rubicon locker?

 

[Temperance]

Hi @Temperance, this is awesome and I appreciate the writeup. I have a Mojave and I plan to get an ARB air locker. I plan on buying the Rubicon front+rear locker switch - using your wiring products, will I need to only buy the Air Locker Control, or both the $160 Air Locker Control and the $70 Front Locker Wiring Harness?

Thanks!

You'll need one locker control for each ARB locker. So if you're just doing the front you will only need one. You'll also need either the front locker wiring harness from my site or the wiring harness bundle from Jeep for a Rubicon. They're both about the same price but the one I sell is easier to install and isn't back ordered.

 

[Temperance]

This is definetely something I want to do, thanks for putting this together. Will your locker wiring harness work with the Eaton E locker or is just for the factory Rubicon locker?

The Mojave front locker wiring harness uses the same gauge wires as the factory one so it'll support up to 8 amps. I believe that the Eaton locker uses less than 5 amps. You will however, need the Z Locker OEM from Z-Automotive. This works similarly to the locker module I made but it just senses voltage to the locker to provide the correct status.

 

[Beemer533]

Thanks, that makes sense.

 

[outdoor.adventures]

You'll need one locker control for each ARB locker. So if you're just doing the front you will only need one. You'll also need either the front locker wiring harness from my site or the wiring harness bundle from Jeep for a Rubicon. They're both about the same price but the one I sell is easier to install and isn't back ordered.

Thanks!

 

[JohnQ]

The Mojave front locker wiring harness uses the same gauge wires as the factory one so it'll support up to 8 amps. I believe that the Eaton locker uses less than 5 amps. You will however, need the Z Locker OEM from Z-Automotive. This works similarly to the locker module I made but it just senses voltage to the locker to provide the correct status.

Hi Temperance. Does it have to be the OEM Z Locker or will the one for aftermarket lockers work? I bought your harness and the factory Rubicon switch. I am putting in an Eaton E locker and I wanted to make sure I got the correct parts. The OEM Z locker is out of stock and the aftermarket one is instock currently.

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