Jeep Wrangler TJ Rubicon Factory Locker Bypass (use your lockers in 4 Hi)

Alright, this post is going to be a cluster, so buckle up.

I'm doing the full bypass (jumping pins 6/7 with ground), but I want a bit more safety then being able to engage the lockers "any time." I'd hate to be cruising down the highway, reach for my coffee, and grenade my diff because I nudged a switch. My original idea was to install another in-line switch on the ground side, so that I would need to flip it before the lockers would engage. Something like below, where V2 and V3 are pins 6 and 7, and the ground is pin 1. You would need to flip S6 before either locker would engage.

Screen Shot 2020-04-07 at 10.31.05 PM.png


But then I decided to get all fancy pants and install some lighted OTRATTW switches. So now I'm not sure if any of this wiring makes any sense. Here's the schematic I came up with, with the caveat that I have no idea how to make wiring schematics.

Screen Shot 2020-04-07 at 10.18.54 PM.png

S1 will be the "locker power" switch, which will need to be actuated before the lockers will work. The best way I could figure to accomplish this was to, again, interrupt the grounds. But I also wanted the lights on the individual F and R locker switches to turn on only after the locker power switch was flipped (V1 is a dash light power source).

So my question is this: Do I have too many grounds tied together? Should the ground for the lights be independent of the ground I use for Pin 6 and 7?

The backs of the switches will basically look like this
Screen Shot 2020-04-07 at 10.00.06 PM.png


ihave.jpg
 
Make it simple and pretend there's no wiring or switch for your lockers at all. Install your own switches and wiring, it's as easy as wiring two switches like you're controlling two 12v light bulbs but they're compressors instead. No need for relays at all, those little compressors don't draw enough current for that. They also shut themselves off automatically when there's the required 5 psi of pressure in the system.

I installed these two switches for my Rubicon locker compressors, they are 100% independent of each other so you can turn them on in any order you want. Each switch/compressor is fused with a 5 amp fuse.

Locker Switches 2.JPG
 
  • Like
Reactions: billiebob
Will tying straight into the compressor with a switched 12v source still allow the dash lights to operate? It's not necessary, but it would be nice.
 
Here's what I settled on

Screen Shot 2020-04-15 at 10.41.39 PM.png

Power comes in to the overhead "locker power" switch from a 5A fused source in an auxiliary fuse block. Power to the overhead switch LEDs is supplied by the Orange/ Brown panel lamps feed wire that I T-tapped into (which also allows me to dim the overhead switches with the gauge cluster). This will allow the switch's lower LED to illuminate only when the headlights are on. The upper LED will illuminate when the switch is actuated regardless.

Once the overhead switch is actuated, power flows to the two locker enable switches in the dash, which also supplies power to those switches' lower LEDs. I was nervous about splicing into the factory pump wiring as Jerry suggested, so as each locker switch is actuated, power will flow to pin 87 in the locker relay slot in the PDC, causing the locker pump to cycle.

1587005705102.png


1587005734445.png


1587005755307.png


I had some spare connectors the same size as the pins on the stock locker switch. I was able to pry apart the locker switch harness and use the tiniest screwdriver I had to extract pin 1 and allow me to connect directly to it rather than try to slip a wire into the backside of the harness like in the original instructions.

1587005997108.png


1587006016063.png


1587006086755.png


1587006112923.png

threw on some heat shrink to keep things together. Now I can leave the locker switch disconnected.

At the PDC I used some male quick disconnects, which fit nicely into the relay pin slots

1587006227943.png


1587006254894.png



Jerry's version would have been much simpler, but it wouldn't be my project if it didn't involve making extra unnecessary work for myself constantly.
 
This is copied from http://www.wanderingtrail.com/Mods/TJLJmods/Locker_Defeat.htm

Just wanted to make sure the information is not lost. @Chris feel free to remove this post if you think it will have issues with copyright.


Rubicon Locker Bypass
The Rubicon came with lockers, but DC decided to add a little bit of safety. So you can't engage them above 10 mph, at 45 mph they disengage (45 in 4-low = scary), and you have to be in 4-low. Well I didn't like this idea of having to be in 4-low to engage them. I like my options. I don't think that I will need to use it anytime in the near future, but since I had the parts I figured why not install it. Now this installation just overrides the shifter position and nothing else. So you still have the requirement of being under 10 mph to engage and they will automatically disengage at 45 mph.

Additional Parts:
Wire
Wire end connectors
Safety switch (Pilot PL-SW26)
Tools Needed:
Soldering Gun/ solder
small flat tip screwdriver
Phillips screwdriver
Drill



Installation:
First thing I did was figure out where I wanted to mount the switch. A few others mounted it down by the 4wd shift lever, but since I had my CB box in behind there I couldn't put it there. So I looked at that flat spot on the dash where the air bad switch goes on the 2003's. Close and convenient to the locker switch, so I wouldn't need to run wires a long distance.​
So once again I disconnected the battery and slowly pulled up the defroster panel.​
I then removed the 2 center surround screws and pull off the center dash surround.​
Now you will need to remove the switch panel. Unscrew the 4 screws and pull it out.​
I found this switch at Autozone for $10. Now while it isn't waterproof, I would be a little less concerned about the switch if I was into water waist deep inside the Jeep.​
I looked at the back of the flat area, and marked the position for the switch and drilled the hole. After I got the switch mounted I turned my attention to the locker switch.​
I already new that I needed to ground the red and white wire to the black wire via the override switch, but I didn't want to splice into the wires. I carefully looked at the locker harness and saw that I could open it up with a small screwdriver. Once I got the harness open I could see that there was enough room to insert a wire down along the original wires next to the metal connector. This would give me good contact and not damage any wires. I carefully installed connectors on the ends of 2 wires and then stripped and soldered the ends of the others. I gave it just a light solder to allow the wires to flatten out so that I could install them. I was able to put the wires in to the harness without this step. Close the harness back up after you get the wires down inside.​
The great thing is 4 yanks and the only thing left is a switch. No signs that wires were ever installed. Now once you have everything hooked up, time to test. I did this in my garage, (open the door). Start it up, flip the switch and hit the lockers. It was nice to see the lockers come on in 2wd. Okay turn everything back off and put it all back together.​


Here is a diagram showing the other ways to wire in this switch. I don't take credit for this diagram.


After having this installed for a few months, I still haven't used it. I like having the option. I will be moving the switch when I install my power converter. I will probably place it down by the 4wd shift lever like a few others.



Independent Locker Control by Ken White (used with permission)​

Independent control of the Front and Rear Lockers is accomplished by adding 2 Single Pole, Single Throw (SPST) switches, some jumper wires, and connectors to the existing Axle Lock Switch and/or wiring located in the center console.

As with most electrical installations, the first thing that should be done is to disconnect the battery’s negative terminal connection from the battery.

Inside the TJ’s cockpit, gently pull back and up on the defroster ventilation panel located between the windshield and dash. It should easily unsnap without much effort.


Once the vent is out of the way, you will see two ź” Hex/Phillips head screws located on the top of the center console. Remove these and then gently pull the center console facade straight out and upward – it is held in place by 4 spring clips so hold the top and bottom when performing this task.

Once the console facade has been removed, remove the four ź” Hex/Phillips head screws holding the switch panel in place. Pull the switch panel out and you will now have access to the connections needed to accomplish this modification.



The schematic shows the electrical connections that need to be made for this modification. The switches I used are from AutoZone. The manufacturer is Pilot, the P/N is PL-SW26, and the type is Racing Switch with Safety Cover – about $10.00 each. I put both switches in the vacant Passenger Air Bag On/Off switch area.

Connect a jumper wire from Pin 1, or the BK Wire, located on the back of the Axle Lock Switch to the same contact on both switches. Then connect a jumper wire from the other contact on the Front Locker Switch to Pin 7, or the VT/DB Wire. The remaining Switch will control the Rear Locker, so connect a jumper wire from the remaining switch contact to Pin 6, or VT/LG wire. This completes the modification.



Connect the negative battery terminal back to the battery and test. Insert the key into the ignition and turn on one of the switches. You should hear the pump engage and then turn off as well as well see the dash indicator light flashing or in steady on state. Turn the switch off and the light should extinguish. Test the other switch. If everything looks good, put everything back together in the reverse of taking it apart.

View attachment 76916
Rear Engage​
View attachment 76917
Rear Indication​
View attachment 76918
Front Engage​
View attachment 76919
Front Indication​

Theory of Operation

(See section 8W-31-12, 13, 14, and 15, and 8W-80-5 of the FSM)


Since the Relays always have power applied to the D4 and D13 connection, applying a ground to D6 or D11 will cause the Rear and Front Locker Relay to energize, respectively. Once energized, voltage will be supplied to the Rear or Front Locker Pumps. They will turn on until 5 PSI of pressure is achieved, and then the pump will turn off – assuming no air leaks.

The two switches basically bypass the existing Axle Lock Switch and control the Front and Rear Locker Relays independently, as well as sending a Logic “0” to the Instrument Cluster (EMIC). The Front and Rear Locker Indicator lamps function exactly the same as originally designed: slow flashing when lockers are engaged without the axles actually being locked, and steady on when the lockers are fully locked and have sent an additional ground signal to the EMIC.

Two important things to recognize about this modification:

1. The switches bypass all safety interlocks, so the lockers can be engaged at any speed, and in any transfer case setting, and will almost certainly not disengage when going over 45 mph.

2. The Locker Relays always have voltage applied to them, even when the key is out, so the switches must be returned to the open position when not in use. If not returned to the Off position, then there is a possibly of running the battery down if there is a leak in the air lines and the pumps continue to cycle, and/or damaging the pumps.

This modification is performed at your own risk, and I in no way assume any responsibility if you break your drive train using this modification foolishly.

Now that all that legal junk has been said, this modification works well and allows great flexibility when playing!

Ken

Independent Locker Control LED Diagram by Greg Donohoe (used with permission)​

Greg worked out this trick LED setup for the independent locker control.

So if I understand this correctly if I put a toggle switch between 1 and 4,5 I would be able to activate the lockers at any speed and any t case position but only when the toggle switch was on?
 
So if I understand this correctly if I put a toggle switch between 1 and 4,5 I would be able to activate the lockers at any speed and any t case position but only when the toggle switch was on?

If I'm reading your post right, your goal is to be able to engage the lockers at any speed and in any t-case position, right? The easiest way to do that would be to add 2 switches, between 1 and 6, and 1 and 7. Once they were flipped, the lockers would be on at any speed, any t-case position, and could be controlled individually. By putting a switch between 1 and 4/5 you it seems like you would have to flip the toggle, but then would need to hit the factory switch to engage the lockers, which would only engage the rear, then the front, but not each individually. But if that's what you want, then it seems like it would work. Grab a small piece of wire, jumper the pins, and test it out.
 
If I'm reading your post right, your goal is to be able to engage the lockers at any speed and in any t-case position, right? The easiest way to do that would be to add 2 switches, between 1 and 6, and 1 and 7. Once they were flipped, the lockers would be on at any speed, any t-case position, and could be controlled individually. By putting a switch between 1 and 4/5 you it seems like you would have to flip the toggle, but then would need to hit the factory switch to engage the lockers, which would only engage the rear, then the front, but not each individually. But if that's what you want, then it seems like it would work. Grab a small piece of wire, jumper the pins, and test it out.
Thanks for the reply, so yes using the toggle switch as a “safety” because they can be engaged any time but still using the factory switch to actually engage the lockers. So I will give it a try.
 
Make it simple and pretend there's no wiring or switch for your lockers at all. Install your own switches and wiring, it's as easy as wiring two switches like you're controlling two 12v light bulbs but they're compressors instead. No need for relays at all, those little compressors don't draw enough current for that. They also shut themselves off automatically when there's the required 5 psi of pressure in the system.

I installed these two switches for my Rubicon locker compressors, they are 100% independent of each other so you can turn them on in any order you want. Each switch/compressor is fused with a 5 amp fuse.

View attachment 151286

Does your method retain factory safeties?
 
No, they operate the way Jeep would have designed to them if their lawyers hadn't insisted on being part of the design process. Mine now operate how ARB and E-Lockers operate do.

Yes but the good aftermarket lockers are designed to be able to be safely engaged at any speed. Will it hurt the stock locker to have that happen?
 
Yes but the good aftermarket lockers are designed to be able to be safely engaged at any speed. Will it hurt the stock locker to have that happen?
I've never engaged mine at high speed, but I've had them on above 30mph more than a few times.

The real concern is engaging them with a crash lock, where there is too fast of a differential difference. I did ruin a factory rear (that I suspect was already partially damaged by the previous owner) because of a crash lock.
 
Last edited:
If I hadn't kept the OE locker switch installed there'd be an ugly square hole left where the switch used to be.

Selectable lockers can be used at any safe speeds but you need to stopped or at a dead slow crawl to engage them. The Rubicon locker is no different in those respects.
 
  • Like
Reactions: derekmac