- Location
- Denver Adjacent
I'm sure a lot of people are familiar with the first half of this mod. Bypassing the locker relay. For those that are not familiar, the purpose of bypassing the relay is so the locker can be engaged in any drive mode at any speed. That being said, if you drive faster than about 10mph on pavement and turn the locker on, bad things could happen.
I've taken it a step further than just the bypass by also replacing the OE locker switch with a custom Carling switch from OTRATTW. I'll cover the whole thing step by step. This is for O/R and Pro4x equipped trucks only. If you don't have the factory locker, this writeup will do you no good. Also, this was done on my 07. Wiring will be the same for all other years but the wire colors may not. So just be aware you should pay more attention to the pinout of the plugs than the color of the wires.
Tools / materials required:
Phillips Screwdriver
10mm socket and long extension
Wire cutters / strippers / crimpers
crimp connectors
3 red tap splices
Female spade connectors (preferably insulated)
Time required: About 45 minutes
First off, here's the switch:
Standard single pole single throw switch. Lower LED (text area) independent for connection with the dash illumination, upper LED dependent to be on when the switch is activated.
Here is a link to the exact switch I'm using. These are available in a variety of different color combinations from OTR. If you don't see something on the website you want, call and ask. They can build damn near anything.
There's four sections of the wiring schematic from the factory service manual that we will be referencing. For anyone that has downloaded the manual from Niccoclub, these diagrams are on pages RFD-83 and RFD-84.
The first is the pinout of the locker control module:
The 2nd and 3rd are what the wires actually do on the module:
And the final one is the pinout for the switch that's in the dash:
We'll start by removing the lower trim under the steering wheel. Pull the screw next to the center console and under the trim closest to the door. The panel should just pop off. Remove the plugs for the mirror controls (and any other switches you may have there) and set that panel aside. Under the panel if you look just to the left of the steering column, you'll see two 10mm/phillips bolts holding the module in.
I found it easier to get the wiring harness out by unbolting the module.
Once you've got it unplugged, set it aside and cut the tape off the wires so you can see what you're working with.
There's 8 wires we're concerned with here.
Pin 1 - Green/White - Keyed Power
Pin 3 - Black - Ground
Pin 9 - Yellow - Power from locker switch ON
Pin 11 - Gray - Low side locker solenoid
Pin 12 - Blue - High side locker solenoid
Pin 20 - Brown - Power to Diff Lock Position switch (on axle)
Pin 21 - Sky Blue - Power from Diff Lock light in dash
Pin 22 - Green - Power from locker switch OFF
Reference this, to figure out what pins are what:
All other wires remain unaltered.
Pins 9, 11, 12, 20, & 21 can be cut off flush with the connector. Do NOT cut pin 1, or 3. And cut pin 22 about 2-3" up from the connector.
First thing we're going to do is attach pin 11 to pin 3. So using a tap splice crimp the vehicle end of the gray wire onto the black ground wire. This gives the locker solenoid a constant ground.
Next we're going to attach the vehicle side of 9 & 12 together. This passes the 12v from the dash switch directly to the locker solenoid:
And then 20 & 21 together. This takes the power from the dash light and makes it wait for a ground from the sensor switch in the axle. When the locker is successfully engaged, ground will be applied to the circuit making the dash light come on:
Then we take the connector side of 22 that you left long and use a tap splice to connect it to pin 1 for keyed power. This makes sure that the relay has power whenever the vehicle is on.
______________________________________
NOTE: IF YOU ARE NOT REPLACING THE SWITCH WITH A CARLING SWITCH AND ARE JUST LEAVING THE OE LOCKER SWITCH IN PLAY STOP HERE. Going further alters the wires so that the factory switch will not work. You can plug the module back in, reassemble the dash and test.
For those interested in replacing the switch, read on.
______________________________________
From there I used the 3rd tap splice to attach the vehicle side of pin 22 to the black wire also. So the green wire that goes to the switch is now a ground:
That's it. You can now plug your locker relay back in and re mount it under the dash.
Lets move to the center stack.
You can reach in behind the center stack and push the stock locker switch out and disconnect it. And then promptly throw it in the garbage.
Cut all the wires off flush with the connector.
Strip all the wires back and crimp insulated female spades to all 5 wires.
That wiring layout is as follows:
Green - Upper LED ground
Yellow - Power to locker relay
Green/White - Keyed Power
Brown - Illumination Ground
Red - Illumination Hot
Using the OTR wiring schematic, connect the Red and Brown to pins 6 and 7 respectively on the switch. The green wire goes to Pin 8, the yellow to pin 3, and the green/white to pin 2. As pictured here.
You're done. Pop the switch back into the dash, re-assemble the trim under the steering wheel, and test it out.
You'll notice that the indicator on the switch tells you when the switch is on and power is being applied to the locker, but the dash light tells you when the locker is actually engaged. I like it this way as it's kind of a two step verification on functionality.
Here's a few night shots you can really see the illumination. First is just with the dash illumination. And yes, it dims with everything else.
Next is what it looks like when the switch is on.
Enjoy your anytime locker!
I've taken it a step further than just the bypass by also replacing the OE locker switch with a custom Carling switch from OTRATTW. I'll cover the whole thing step by step. This is for O/R and Pro4x equipped trucks only. If you don't have the factory locker, this writeup will do you no good. Also, this was done on my 07. Wiring will be the same for all other years but the wire colors may not. So just be aware you should pay more attention to the pinout of the plugs than the color of the wires.
Tools / materials required:
Phillips Screwdriver
10mm socket and long extension
Wire cutters / strippers / crimpers
crimp connectors
3 red tap splices
Female spade connectors (preferably insulated)
Time required: About 45 minutes
First off, here's the switch:

Standard single pole single throw switch. Lower LED (text area) independent for connection with the dash illumination, upper LED dependent to be on when the switch is activated.
Here is a link to the exact switch I'm using. These are available in a variety of different color combinations from OTR. If you don't see something on the website you want, call and ask. They can build damn near anything.
There's four sections of the wiring schematic from the factory service manual that we will be referencing. For anyone that has downloaded the manual from Niccoclub, these diagrams are on pages RFD-83 and RFD-84.
The first is the pinout of the locker control module:

The 2nd and 3rd are what the wires actually do on the module:


And the final one is the pinout for the switch that's in the dash:

We'll start by removing the lower trim under the steering wheel. Pull the screw next to the center console and under the trim closest to the door. The panel should just pop off. Remove the plugs for the mirror controls (and any other switches you may have there) and set that panel aside. Under the panel if you look just to the left of the steering column, you'll see two 10mm/phillips bolts holding the module in.

I found it easier to get the wiring harness out by unbolting the module.
Once you've got it unplugged, set it aside and cut the tape off the wires so you can see what you're working with.


There's 8 wires we're concerned with here.
Pin 1 - Green/White - Keyed Power
Pin 3 - Black - Ground
Pin 9 - Yellow - Power from locker switch ON
Pin 11 - Gray - Low side locker solenoid
Pin 12 - Blue - High side locker solenoid
Pin 20 - Brown - Power to Diff Lock Position switch (on axle)
Pin 21 - Sky Blue - Power from Diff Lock light in dash
Pin 22 - Green - Power from locker switch OFF
Reference this, to figure out what pins are what:

All other wires remain unaltered.
Pins 9, 11, 12, 20, & 21 can be cut off flush with the connector. Do NOT cut pin 1, or 3. And cut pin 22 about 2-3" up from the connector.
First thing we're going to do is attach pin 11 to pin 3. So using a tap splice crimp the vehicle end of the gray wire onto the black ground wire. This gives the locker solenoid a constant ground.

Next we're going to attach the vehicle side of 9 & 12 together. This passes the 12v from the dash switch directly to the locker solenoid:

And then 20 & 21 together. This takes the power from the dash light and makes it wait for a ground from the sensor switch in the axle. When the locker is successfully engaged, ground will be applied to the circuit making the dash light come on:

Then we take the connector side of 22 that you left long and use a tap splice to connect it to pin 1 for keyed power. This makes sure that the relay has power whenever the vehicle is on.

______________________________________
NOTE: IF YOU ARE NOT REPLACING THE SWITCH WITH A CARLING SWITCH AND ARE JUST LEAVING THE OE LOCKER SWITCH IN PLAY STOP HERE. Going further alters the wires so that the factory switch will not work. You can plug the module back in, reassemble the dash and test.
For those interested in replacing the switch, read on.
______________________________________
From there I used the 3rd tap splice to attach the vehicle side of pin 22 to the black wire also. So the green wire that goes to the switch is now a ground:

That's it. You can now plug your locker relay back in and re mount it under the dash.
Lets move to the center stack.
You can reach in behind the center stack and push the stock locker switch out and disconnect it. And then promptly throw it in the garbage.

Cut all the wires off flush with the connector.

Strip all the wires back and crimp insulated female spades to all 5 wires.

That wiring layout is as follows:
Green - Upper LED ground
Yellow - Power to locker relay
Green/White - Keyed Power
Brown - Illumination Ground
Red - Illumination Hot
Using the OTR wiring schematic, connect the Red and Brown to pins 6 and 7 respectively on the switch. The green wire goes to Pin 8, the yellow to pin 3, and the green/white to pin 2. As pictured here.


You're done. Pop the switch back into the dash, re-assemble the trim under the steering wheel, and test it out.

You'll notice that the indicator on the switch tells you when the switch is on and power is being applied to the locker, but the dash light tells you when the locker is actually engaged. I like it this way as it's kind of a two step verification on functionality.
Here's a few night shots you can really see the illumination. First is just with the dash illumination. And yes, it dims with everything else.

Next is what it looks like when the switch is on.

Enjoy your anytime locker!
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