Brown Wire Mod

[ET2 Burris]

When I first signed up on this site, I remember someone posting a thread about cutting into the wires for the A4WD system to get it to disengage. But from reading that link, the author says that it won't add any added mpg just let's you decide rather than a computer to use only 2 wheels instead of all 4. But cool idea.

Gone are the days of unlocking the from axle, they are...

This is my first Big suv, my toyotas had Downey off road to help them.
I purchased some Warn Man Hubs. have you guys looked for this?

I haven't read the thing on cutting a wire. But the hardware is whats getting you.
If its like the rest of the world it just engages the front drive shaft. "that you are turning the whole time not to metion the diff.

 

[nvycrmn]

can you post pics of which harness you cut from? and just so i get this correct, you technically still have A4WD cuz the front tires are still spinning correct?

 

[panda24619]

well i think the awd is electronic on these transfer case. duh! but i think if it detects wheels slip and the wires cut then it wont send power to the front. idk for sure. im just glad i dont have to deal with what you guy are doing.

 

[ronjeremy6]

slo-ryd, is all still well with this mod? i fried my transfer case last month because i bought two tires instead of four. yes, i'm a moron. lesson learned.

1600 bucks later (tires and transfer case rebuild) the rig is running tip top. BUT, i don't want to worry about this happening again. is the wire viewable from under the truck?

thanks in advance.

 

[markanthony]

I want the ability to disable it for a reason not mentioned.
Say I'm out on the road and one of these 35" tires goes flat or blows out....
I will only have a 265/70/17 spare to put on and the drivetrain will be pissed and/or damaged running the 1 smaller diameter tire no?

Umm. Unless u have a solid locker (non electric,ARB, etc) If you put on a smaller/bigger tire then the rest. The axle will absorb (even with a LSD or LS) a short drive with a smaller tire (I would think no more then 100 miles) with out any damage.

All it would do is run the smaller tire faster then the bigger tire. The spider gears in the open diff would spin off the extra spin. The LS or LSD should slip off the extra spin. If the LSD or LS is (frozen) solid with no movement. It would kill tires faster. If you run the two different tire for a long time. It would kill Diff's, t case, tranny. But I think this would be an extreme case. This would also be why u can run one rear tire at say 25psi and the other one at 45 psi for miles. yes the tire with lower psi would have a funny pattern on it.

I think that putting hubs on the front axle would not really be a Benefit. The t case would still pull the drive line, diff, gears, and axle shafts. All front hubs would do it unlock the power to the wheel and the front u joint. Not disconnected the t case.

On the t case. It has a magnetic unit. It will still "pull" the front tires while off the ground. But with the weight of the truck. their would be no torque to pull the truck.. So yes. killing power would kill the A4wd and still maintain the 4H/L.

 

[99 Expy]

If you were to be able to install hubs on the front, wouldn't that disconnect the 4x4? If the transfer case is what engages when Auto 4x4 is activated, the axle would still spin, but not the tires. Is there a way to install manual hubs on these? I don't like that the front drive train is spinning when not in use due to all of the unnecessary wear on the parts. Anyway, I have a wiring problem so my Auto 4x4 doesn't engage, but 4 hi and lo both work.

 

[Bart Man]

Brown Wire AWD to Two Wheel Drive!!

Well I spent more time reading these post than it took to the job! I just cut the Brown Wire on the transfer case and tried it out in the snow! It works GREAT! 4 HI an 4 LO works great also!, I now have 2 wheel drive! I may hook up a toggle switch in the cab for AWD

 

[panda24619]

Well I spent more time reading these post than it took to the job! I just cut the Brown Wire on the transfer case and tried it out in the snow! It works GREAT! 4 HI an 4 LO works great also!, I now have 2 wheel drive! I may hook up a toggle switch in the cab for AWD

at least someone tryed this! now maybe others will too! i dont have to worry about this but hope it works for you guys that do do it. a switch would be good too.

 

[Bart Man]

It doesn't get any easier thanks again!!!

 

[schmeg]

Brown Wire

Sounds like I'll be doing mine this spring. Along with synthetic gear oil in all three cases.

 

[ExpeditionDrew]

All i did was pull the #104 fuse and what do ya know...i can now do a burnout....not that's all i wanted to do.....but driving afterwords for about an hour i did notice a 1.5-2 mpg gain through my OBDII reader...although i cant really tell any difference in acceleration. But i think eventually i will put in a toggle switch once winter gets closer.

 

[99-4wd]

i just removed the front drive shaft. to me the trucks rides so much smoother and i can also make a smooth u turn without the binding feeling.

highly recommended, if u dont need 4 wheel drive. i only use it in the winter anyway.

 

[Bart Man]

That's alot of work when you can just pull a fuse or cut the brown wire, plus there shouldn't be any binding when you make a turn no matter how tight the turn is! Unless you transfer case is in gauging

 

[99-4wd]

Its actually not alot of work at all prerty easy and straight forward.

 

[markanthony]

To sum up the thread.

Brown wire mod: all this does is kill the power from the computer to the clutches, so that it will not engage the awd or a4wd. There still is power being applied from the transfer case to the front end, but not enough to do anything. There should not be any front wheel pull when the truck is on the ground. With a switch installed. There is total control with out getting out to put in hubs, or replace a fuse.

Hubs (manual or automatic) driveline pull: If you can find a set of hubs for our trucks. All these do is disengage at the wheel. NOT THE TRANSFER CASE. the complete front axle assembly will still turn. At this point you have MPG loss due to having to pull the system To pull the drive line. There is quite a bit of work to get it done. then there is installing it when it is needed again. For me. I like to have the front drive line there. even if it is just turning and not really doing anything.

pulling the fuse: ALL THIS DOES IS COMPLETELY DISENGAGE THE TRANSFER CASE. YOU WILL NOT HAVE ANY 4WD HI OR LO. ONLY 2WD. This just kills the power to and from the case.

I feel it would be a better deal to install a switch to the brown wire, then to anything else. It does not seem to be very difficult. It can be done under the car with out removing to much. The choice is there to just cut and cap, remove, or install a switch. keeping in mind that when the truck is off the ground. The front tires will turn. The system will still turn when driving. But their will be not be enough to turn the tires. I would assume that this can or could wear out the magnetic/electric clutches for the awd drive with slippage. I can not say for sure. just seems logical that something there would wear with the brown wire cut.

I have not done this to mine yet. I have pulled the fuse for research. I will attempting to this mod this weekend. I will to a full write up with pics and post it up for everyone on Monday..

I hope this helps future readers. Sometimes it helps to have all sides listed on one page to read or understand.

 

[BakerEdition]

I have an AWD...I get NO binding on turns at all...I thought I read here that the AWD really don't kick in unless it feels slippage...or like hydroplaning...MPG shouldn't change either way....I admit I bought as it was posted as a 4x4...it didn't say anything about AWD..but Im glad I have it...

 

[Expeditionary]

awd sucks... sorry, thats why I bought a 97 instead of 99+. I LOVE doing donuts and tearing Sh*t up in places im not rly supposed to be (illegal wheeling)

 

[pooleo8]

meh, to many pages to read thru. I have done the mod. The thing I hated was the truck deciding when to lock in, it almost caused a roll over the first winter, trying to correct, then it locks up. Bad deal. Anyhow, I just went down to the T-case, snipped the wire. Left enough room to hook it back up if needed. Best 4 sec mod ever.

 

[spt87a]

Disable A4WD = much improved tire life

I've run my '99 Expedition for years with the 4wd system fuse pulled. Originally I did this because it started acting up - it would engage the front wheels 100% of the time and only stop once I hit 35mph when the sytem would error out and disable itself. This would only last until the next trip (engine shutoff then restarted).

For a long time I assumed there was a bad speed sensor so I just lived with it as is and would put the fuse in those times I wanted 4HI or LO. Now I suspect the trouble may have been caused by not replacing all 4 tires at once so the difference in tire diameter was causing the problem.

The big benefit I noticed after running with the fuse pulled is my front tire life dramatically increased. Prior to that I was only getting 20K or so out of the front tires before they were cupped. So either my A4WD was misbehaving from the time this Expedition was brand new or this system is just not quite ready for prime time.

Anyway - I'm going to give this brown wire mod a shot so I don't have to mess with the fuse anymore to use 4hi or lo.

I doubt the brown wire mod will cause any excessive wearing of the clutches. If the default is to send 5% power to the front - that is likely with 0 electical power applied to the clutches so disconencting the fuse/brown wire is just preventing that percentage from being increased. My 3-4 year run with the fuse pulled hasn't resulted in any transfer case issues so I think that is a pretty solid test (221,000 miles on this vehicle so far).

 

[FloorIt]

I did the brown wire mod prior to installing my 37" tires and have not noticed any adverse affects.