How to: The Comprehensive Brown Wire Mod Thread

[gijoecam]

Some of the Explorers could... TSB 02-25-8 specifies the part numbers and lists the makes and models. IIRC, the Rangers were hit-or-miss there too... some could, some couldn't. Probably had to do with some of the wiring and/or the GEM programming capabilites.

No worries.

-Joe

 

[greggj]

I have a 04 explorer. the front diff makes a whining noise. can i do the bwm to an 04 and if so would it eliminate problems with front diff? oyea it is a v6 auto 4wd it has auto hi and low buttons.

 

[gijoecam]

No. The front diff will still turn at all times. It is a live front axle.

 

[greggj]

will the bwm work on an 04 model?

 

[gijoecam]

Not exactly... If my memory serves, it cannot be reset after disconnecting it.... it sets a trouble code that doesn't clear until you cycle the ignition.

 

[danman89]

Instead of pulling the das apart to bypass the gem, can you run a wire direct to the wire connector at the transfer case motor, simply for test purposes?

 

[IZwack]

Yeah anywhere will work really. Some people intercept the wire at the floor.

 

[danman89]

Just so i am clear, if i simply tap in even as it enters the tcc, and hook it to direct powere, even the positive battery terminal, it should disengage from 4hi and in a sense it will force it to stay in 2wd?

The reason why ia m asking is i have replace everything else including the the transfer case and it still stays in 4wd. It will go in and out of 4hi & 4lo but it will not go into 2wd.

 

[gijoecam]

Yes, you could, but if it's for testing purposes, just unplug the transfer case connector all together. Easily reversible, no splices... reconnect when testing is complete.

 

[gijoecam]

Just so i am clear, if i simply tap in even as it enters the tcc, and hook it to direct powere, even the positive battery terminal, it should disengage from 4hi and in a sense it will force it to stay in 2wd?

No. Cutting the power to the transfer case prevents the transfer case from locking, thereby forcing it into 2wd only. Applying power to the brown wire going into the case LOCKS the case in 4wd.

The reason why ia m asking is i have replace everything else including the the transfer case and it still stays in 4wd. It will go in and out of 4hi & 4lo but it will not go into 2wd.

You do not have a true 2 wheel drive mode from the factory... If you're experiencing the binding, check out the 'Second Gen 4wd Troubleshooting' thread. The short version is unplug the t-case and see if the binding persists. If it goes away, it's electrical. If it persists, it's mechanical.

-Joe

 

[danman89]

Ya i tried that, remember, see above.
I disconnected the wire connection and still have front traction. I then replaced the transfer case and it is still stuck with front traction (used transfer case). Therefore it is electrical or the GEM sendign the wrong signal.
That is why i am asking how to bypass the GEM to test the transfer case.
At this time it seems that it might ne be mechanical???

 

[gijoecam]

I then replaced the transfer case and it is still stuck with front traction (used transfer case). Therefore it is electrical or the GEM sendign the wrong signal.

How can the GEM send ANY signal if the transfer case is disconnected?

And how does any of this diagnostic relate to the brown wire mod?

 

[danman89]

I seem to get numerous answers from numersous people even the local ford dealer.
If i replaced the TC and the replacement was not locked in 4WD when i installed it but when i test drove it it went into 4WD and will nto come out.
Therefore it is not mechanical, what is forcing it into 4WD.
Even when i disconnect the replacement TC it still stays in 4WD, so is it a huge coincidence that the same problem hapened to 2 Trasfer cases at the same time?

 

[gijoecam]

I seem to get numerous answers from numersous people even the local ford dealer.
If i replaced the TC and the replacement was not locked in 4WD when i installed it but when i test drove it it went into 4WD and will nto come out.
Therefore it is not mechanical, what is forcing it into 4WD.
Even when i disconnect the replacement TC it still stays in 4WD, so is it a huge coincidence that the same problem hapened to 2 Trasfer cases at the same time?

I think you may not be clear on how the transfer case functions... Let me see if I can clarify a bit... If you disconnect the connector at the transfer case, there is no possible way that the computer can somehow force the 4wd to remain locked. Unlike a conventional transfer case (like the 13-54 in the first-gen Explorer, for example) which uses a lockup collar moved into place by a shift fork (actuated by either a hand lever or an electric motor) there is no significant movement that takes place. In simpler terms, Think of it as working like an AC compressor clutch: Apply power: Engage 4wd, remove power, disengage clutch.

Now, if you're driving down the road and the connector at the transfer case is disconnected, it's not possible for the GEM to keep the transfer case locked. It did not 'shift' anything to start with. Cutting the power by using the brown wire mod or by unplugging the transfer case has the same net effect on the transfer case as would unplugging the connector on the AC compressor clutch: At that point, it instantaneously releases and can no longer engage of its own free will.

The ONLY possible way for it to remain locked is in the event of two things: Mis-matched sizes of tires that cause the driveline to stay bound up after it releases, or catastrophic mechanical failure of the transfer case clutch jamming the clutch assembly in the locked position.

So, with that in mind, do you understand why I'm suggesting that it must be a mechanical issue and really can't be an electrical issue?

 

[Sploderdozer99]

so if i locate the brown wire under the driver seat do i just need to cut it and run each end to a switch and then it should work properly?

 

[pinstripefan90]

I have herd that even if you don't go apeshit and really don't spin your wheels much it can still take out the clutches in your transfer case, and even w/ the switch in the off position it is truely never 2wd, i feel like it should be left the way it was...
- Jake

 

[HASO]

O K

If I don't need 4auto any more .. can I use the same switch or i have use also the exta switch

 

[steelo1]

If you choose the underseat wiring option, to put switch in console, its just basically cut wire, join extension wires then join those to say, an on/off flip switch. For lighted switch just add a 3rd wire to ground, is this right? obviousely using correct amp wires.
Looking at underseat for ease & also mines a r/h/drive so not to sure about correctness of your pics & left/right instructions.
Thanks

 

[Glen4X4]

I would imagine the wiring would still be going through the left hand side of the truck since the driveshaft for the diff and t-case are on the right side. It isn't that hard to pull a couple trim pieces and unbolt the seat to make sure of this, but pretty sure the floor pan is the same.

 

[austinmob]

Thanks for the thread. Ive installed my switch.

1 question though.

I disconnected the plastic wiring coupler at the TX case some time back until i got around to doing the switch. The 4x$4 lights on the dash flashed periodically which i know is normal. Now that i have the switch in place, the lights no longer flash.

Should they still flash when the Brown wire is switched off or does the modification overide the computers ability to determine if their is a problem.