Homemade Old School Plug and Play Locker Bypass

[Retired BLM Rig]

Just a few words about the 4th gen resistance issue:
When Ram changed to the Borg Warner transfer case in Jan. 2012, the TCPS 4Lo resistance also changed and based on the testimony of others I assume it changed to 60 ohms.
Based on what ACBoomer16 posted on page 1 of this thread, we know that the 4Lo resistance of a 2016 truck is 49.2 ohms.
What we don't know is when did it change from 60 ohms to 49.2 ohms and is it still the same for 2017?
To answer these questions will require some detective work and input from the 4th gen guys that are interested in doing this mod.
I'm just trying to help fill in the locker bypass void that currently exists.

[olyelr]

I'm just trying to help fill in the locker bypass void that currently exists.

And we all are thoroughly pleased about that! Thank you for dedicating your time for folks like us with these newer nannie trucks!

[rkgzx9leftcoast]

Yes, Thank you for your time and dedication on this item. I am definitely interested in its progress, and would get one if/when it is available.

[NickPic83]

I would be interested as well

Sent from my XT1650 using Tapatalk

[aearles]

I'm in a 2015 and I'm more than happy to dig into the electrical system to contribute, if there's anything you want me to check or try, just let me know.

[Retired BLM Rig]

I'm in a 2015 and I'm more than happy to dig into the electrical system to contribute, if there's anything you want me to check or try, just let me know.

What I would like to find out is the ohm reading across the two terminals of the transfer case position sensor, when it's shifted into the 4X4 Low position, for each model year truck from 2012-2017. If you want to supply a reading for a 2015 truck, that would be great! To do this you need to unplug the sensor located just above where the shift linkage enters the T-case and then probe the sensor terminals with an accurate ohm meter. It's easier said than done, the access is very limited. It might be easier to just remove the sensor and bench test it.

If any 4th gen guys have a factory service manual, the sensor specs should be available in there.
Thanks for offering!

[olyelr]

What I would like to find out is the ohm reading across the two terminals of the transfer case position sensor, when it's shifted into the 4X4 Low position, for each model year truck from 2012-2017. If you want to supply a reading for a 2015 truck, that would be great! To do this you need to unplug the sensor located just above where the shift linkage enters the T-case and then probe the sensor terminals with an accurate ohm meter. It's easier said than done, the access is very limited. It might be easier to just remove the sensor and bench test it.

When I get into mine, maybe this weekend maybe not, I will see what kind of number my truck has... that is if I can figure out how to work an ohm meter

[2010PWERWGN]

According to service information from late 2012 through 2017 the resistance should be 60.4 ohms +/- 1%. Hope this helps.

[Retired BLM Rig]

According to service information from late 2012 through 2017 the resistance should be 60.4 ohms +/- 1%. Hope this helps.

That's what I thought too until I read the post from ACBoomer16 on page one of this thread.

Finally had a chance to install old school bypass in 2016 power wagon. 60 ohm resistance was not correct in my Truck. Read resistance of factory switch (49.2 ohms). Readjusted potentiometer to 49.2 ohms and checked bypass. All works as it should.

That's why I'm looking for test results from each model year, so we can get to the bottom of this mystery.
Thanks for the input.

[Retired BLM Rig]

I'm beginning to wonder if maybe ACBoomer16, when he came up with the 49.2 ohm reading, was using a meter that wasn't properly zeroed/calibrated. Maybe all the newer 4th gens really are 60 ohms.

[2010PWERWGN]

I had parts look up a t-case position sensor for a 16 and came up with 68211454AA and says it fits 13-18.

[Retired BLM Rig]

Confirmation.

[olyelr]

Yep, this setup worked on my '16. Needed the resistance set at 60 ohms. 47 ohms = no worky.

I haven't done much of any testing yet, but will update soon.

[olyelr]

Well I had a smidgen of time for a small amount of testing with this by-pass setup and here are some conclusions I have come up with...

Pros:
- Locker(s) work in 2WD and 4HI.
- ESC system is apparently fully off according to dash light and dash message (but I have not fully determined this).

Cons:
- Throttle mapping is so severely different that anything more than 1st or 2nd gear is very odd shifting - forget driving down the road at speed using it, its just too far off.
- I think ABS is still functional.
- For some reason using this will engage the CAD. While not a big deal, I did notice that when I pushed the button while slowly moving there was a notable BANG (I think from the front axle). Not really sure why, as I would think it is the same as shifting into 4WD on the move which doesn't have an audible bang.

That is about all I have at the moment. I sure wish there was some snow around for testing this setup. It is hard to determine if the ESC system is truly off. Same with the ABS... I am just not sure yet... but since it is normally on in 4LO anyway, I am sure it still is on using this setup too.

[Retired BLM Rig]

I tried mine tonight on my way home from work and have to say that I really don't notice that big of a change with the throttle responce and trans shifting. On my truck it seems more subtle. I know other 3rd gen guys have complained about those issues too though, so I know it's not a generational thing. There's not much point in using the bypass at highway speed since the lockers and sway bar functions turn off above 18 MPH. I guess the main thing that still needs to be determined is the level of control (if any) you regain over the ABS and ESC. If that's still an issue, there's still the second set of control wires tucked inside the harness that could be connected to a second relay to turn those off completely.

Thanks for the update and feedback Olyelr, I'm looking forward to hearing more!

[Retired BLM Rig]

Well, it doesn't look like this will work well on the newer trucks with CAD, just a little too sensitive and glitchy.
You guys would probably be better off waiting for the newer development that Pit Slave is working on.

[TwinStick]

What are the 3rd gens supposed to read ? Just curious. I have a new one but i have a Harbor Freight free cen-tech meter & it reads 62 consistently. Anyone know ? Thanks.

[olyelr]

Well, it doesn't look like this will work well on the newer trucks with CAD, just a little too sensitive and glitchy.

I think if you keep it slow and dont get into shifting too much it works fine. But the throttle mapping change and shift point change is pretty screwy to say the least.

I will have to check out what Pit Slave has brewing up. I didnt know there was anything going on...

[Retired BLM Rig]

What are the 3rd gens supposed to read ? Just curious. I have a new one but i have a Harbor Freight free cen-tech meter & it reads 62 consistently. Anyone know ? Thanks.

If you're talking about the 3rd gen T-case position sensor resistance values, here they are:

• 2H = 1172 - 1175 Ω
• 4H = 677 - 691 Ω
• Neutral = 406 - 415 Ω
• 4L = 208 - 213 Ω

[OldSchool2]

I tested my 2017 trucks resistance in 2H, N and 4L. Rounding the numbers my readings where; 2H - 40 ohms, N - 20 ohms, 4L - 60 ohms. It's easy to test your trucks resistance in each position. Take your new plug end with the wires attach to an ohm meter, attach it to the transfer case and without starting your truck change the transfer case gear selector and you can read the resistance of each position. I wondering is the 49 ohms resistance is the 4H position.

[TwinStick]

What are the 3rd gens supposed to read ? Just curious. I have a new one but i have a Harbor Freight free cen-tech meter & it reads 62 consistently. Anyone know ? Thanks.

If you're talking about the 3rd gen T-case position sensor resistance values, here they are:

• 2H = 1172 - 1175 Ω
• 4H = 677 - 691 Ω
• Neutral = 406 - 415 Ω
• 4L = 208 - 213 Ω

So, way different than the new ones. Thanks.

[SolarDude]

The plug and play bypass kits that used to be available that allowed the use of the factory knob seemed pretty dialed but they don't seem to be available. What about just intercepting the wires coming from the diffs? Couldn't we just install toggle switches and just disregard the factory switch and all the mapping issues? If I was able to find factory plugs I could disconnect the factory pigtail and tuck it away so it could be reinstalled later and create a new pigtail with a new 12volt source?

[Reloaderguy]

The plug and play bypass kits that used to be available that allowed the use of the factory knob seemed pretty dialed but they don't seem to be available. What about just intercepting the wires coming from the diffs? Couldn't we just install toggle switches and just disregard the factory switch and all the mapping issues? If I was able to find factory plugs I could disconnect the factory pigtail and tuck it away so it could be reinstalled later and create a new pigtail with a new 12volt source?

Originally I was going to buy the factory connectors and then build a Y intercept harness with diodes for the OE upstream side. I have the connectors but was able to get a PNP bypass so I did not pursue the project. If I were in your shoes I'd build a bypass with hardwired switches mounted in the plate above the e-brake release.

[olyelr]

The plug and play bypass kits that used to be available that allowed the use of the factory knob seemed pretty dialed but they don't seem to be available. What about just intercepting the wires coming from the diffs? Couldn't we just install toggle switches and just disregard the factory switch and all the mapping issues? If I was able to find factory plugs I could disconnect the factory pigtail and tuck it away so it could be reinstalled later and create a new pigtail with a new 12volt source?

Originally I was going to buy the factory connectors and then build a Y intercept harness with diodes for the OE upstream side. I have the connectors but was able to get a PNP bypass so I did not pursue the project. If I were in your shoes I'd build a bypass with hardwired switches mounted in the plate above the e-brake release.

PNP bypass?

[Reloaderguy]

Plug and play.