4x4 Auto disable?

[P. doggy]

I am sure this has been asked before, but does anyone know how to disable the Auto 4x4 on an '02 Explorer? Or, possibly know a wire, so I can put a swithc on.
Thanx, Jared G.

 

[kert0307]

Well, in 95-01 expos, there's a brown wire under the drivers seat you can do that to. I'm not sure if the 3rd gen expos have it though. Search for "brown wire mod"

 

[gijoecam]

For '02, there were some changes to the wiring. The BWM works, but doesn't.... It'll deactivate the 4wd, but the lights start flashing. They changed the ground loop for the clutch and re-routed it back to the GEM instead of going to a chassis ground. If you just clip the wire, the system doesn't know why the power's not going through the loop and returning so it flashes a code. In theory we could bypass it with a DPDT on-on switch and a resistor, but nobody's tried it yet.

I've discussed it a few times.... search and ye shall receive.

 

[rocco123]

My truck has a traction control switch ('02 limited). Will this de-activate the 4X4 for better milage?

 

[gijoecam]

No it will not, and disabling the 4wd will not increase the fuel mileage either.

-Joe

 

[joefnh]

Brown Wire Mod

I have an 03X 4.0L 4x4. The BWM works, with the brown wire found in the passenger side door jam. I installed a relay & switch combo with an additioanl indicator light. This has worked well for the past 6 months and did not result in any flashing lights

--Joe

 

[gijoecam]

aaack... he said '02 Limited' and I saw, "02 with a v-8 and all wheel drive". The BWM only works on those vehicles with the Automatic 4wd. If you have a v-8 with all wheel drive, it will not work.

At any rate, it will not help the fuel mileage.

Also, it appears that the 02 MY still has a chassis ground for the transfer case clutch coil. The '03 does not. There is likely some programming change to the '03s where the 4wd control module looks for the return signal to be there when current flows through the clutch. What it uses this for is beyond me, but I'd love to talk to the engineer that designed the system!!

-Joe

 

[rocco123]

It is a '02 limited W/V8 & W/traction control.

Thanks for the info GIjoe.

 

[P. doggy]

Hey joefnh, if you have any more details on where exactly the BW is on your X and what type of relay you used, I would greatly appreciate it.
Thanx, Jared G.

 

[P. doggy]

3rd Gen BWM

So I did what Joe suggested, I put in a relay. This is the procedure I used on a 2002. It should work on up to a 2005. These are the steps I followed. I am not saying this is the best and this is just a guide. Feel free to ask me questions, but please do not hold me liable. Give your self about 2-3 hours to be safe.

1. Start by removing the dash piece around the radio, center vents and air control. I applied a flathead screwdriver to the bottom of the plastic dash piece and pried up. This might leave a small mark in the dash piece below it, where the shaft of the screwdriver rests. Be careful. The dash should pop out. If you can, pull up and out on the piece. It should gradeually start poping off. There are about six pops that should happen.
2. Mount the switch. I wanted mine in a easy-to-reach spot and visible. Since I have an XLS, the spot in the pics works great. It is also easy to replace the small dash piece if needed. I also used a lighted switch, so I needed power for the light. I used the second wire from the right on the wiring harness to the 4x4 option buttons.
4. Run the wiring. I grounded my switch out to the radio. The red wire that is spliced into the 4x4 harness, I ran to the power input on the switch. The acc. or load wire on the switch, I ran behind the glove compartment. You can make the glove comp. swing all the way down by squeezing the catches inward. After it is all wired, check the switch. Turn the key to the on position and check the switch. Should light up. Carefully replace the dash piece. Make sure not to pinch any wires.
5. Find the Wire. If you remove the step plate, there is a wire channel underneath. Remove the top cover of the wire channel; it is black and made of plastic. This will now show 2 bundles of wires; one large and one small. You want the small bundle. The plain brown wire is the one of interest. You will also want to pull off the lower plastic piece, on the far right-hand side, under the glove comp.
6. Install relay and wires. Cut the brown wire. Strip the ends and crimp or solder on a wire to both sides of the brown wire. There should be three bolts where you pulled off the plastic under the glove comp. One should be bare. This is where I mounted my relay and grounded out my relay. If you do not have a mount, you can it tuck back in the body. I used a 12V/30A relay. In this photo,
Yellow = Ground
Green = Switch
Black = Input from brown wire
White = Output to Brown Wire
7. After it is all hooked up, check it out. Start the vehicle. if the light is on on the switch, all 4x4 options should work. If the light is off, it should be 2x4, and the 4x4 light on the gauge panel should not flash.
8. Put the plastic back on. Take for a test drive. Should work.
I have pics of all the steps. I can send them to you in the order of instalation. Or, if you can post them for me, that would be great.

Cost: about $20-$25
Time: if all goes well, 2 hours.
Result: Burnin Rubber!

Have Fun, Jared G.

 

[gijoecam]

Awesome! Glad someone finally tried it!

e-mail the pics to gijoecam@yahoo dot com and I'll up-load them to my gallery.

Also, if you have a sketch of the wiring schematic, that would help too.

-Joe

 

[gijoecam]

I got the pic posted in the gallery in my signature. Use the pull-down for "3rd gen Explorer BWM."

Didn't have time to post them here. I also need to convert the document with the schematic into a JPEG to upload it. Looks like I'll be updating the Comprehensive Brown Wire Mod thread now.

-Joe

 

[88OrangeLX]

How is stopping power from going to the front wheels not going to save you gas? That doesn't make much sense!

 

[gijoecam]

How is stopping power from going to the front wheels not going to save you gas? That doesn't make much sense!

Because everything up front is still turning, whether it's being driven through the driveshaft or through the road. You're not reducing the parasitic drag on the powertrain. Cutting the power to the front wheels doesn't stop anything from turning, therefore there is no power savings, and therefore, no fuel savings.

-Joe

 

[jsdoigantiques]

I have an 03' Explorer XLT. There seems to be alot of complicated unecessary info about the brown wire mod for the 3rd gens. In the passenger side door jam, there are 2 wire bundles. In the smaller bundle, just cut the solid brown wire and put a switch to it (the switch is necessary because once it is cut the wire your full time 4x4 wont work, although the indicator light says it is on) No flashing lights or indicators, works perfectly, takes about 5 minutes. Just get some wire and a switch, mount it wherever you want.

 

[gwguidi]

Why do the mod

Because everything up front is still turning, whether it's being driven through the driveshaft or through the road. You're not reducing the parasitic drag on the powertrain. Cutting the power to the front wheels doesn't stop anything from turning, therefore there is no power savings, and therefore, no fuel savings.

-Joe

If it does not save gas why do the mod? I would think it would save gas because the with out exact tire size because of tire pressure or wear there would be power lost when the clutch is cycling.

 

[mudmonger]

If it does not save gas why do the mod? I would think it would save gas because the with out exact tire size because of tire pressure or wear there would be power lost when the clutch is cycling.

The reasons for doing this range from juvenile (smoking tires) to varying degrees of usefulness. One example would be the fact of being able to go into low range in 2wd. Nice if trying to pull something up a steep asphalt hill or on concrete. This would smoke your front u-joints in 4wd low. Kind of a swiss army knife type of mod if that makes sense.

There is no fuel gain because under normal circumstances your front end is not powered unless it slips, that is the difference between 4wd auto and all wheel drive. In the latter there is a viscous coupling in place of the transfer case that acts like a limited slip between the front and rear axles so they can be powered all the time with out damage.

I can't think of a use for it for myself, but if I towed or ever pulled anything I would do it. There would be some uses off road as well, especially in wood trailing. Peace out.

DMC

 

[Carguy3J]

So I did what Joe suggested, I put in a relay. ............
Cost: about $20-$25
Time: if all goes well, 2 hours.
Result: Burnin Rubber!

Have Fun, Jared G.

That is a great way to destroy an otherwise perfectly good transfer case. This "mod" is not intended to allow for burnouts. In fact, it's pretty useless by itself. Now, if you have a way to disconnect the front diff from the wheels, then you could do the BWM as well, to prevent the front driveline from getting power.

Someone else suggested using it as a way to get 2wd LOW. Bad idea. This is gonna put some weird stress on the internals. It would kinda be like having to carry a 50lb bag of cement in one hand, and a feather in the other. You'd be "off balance".

Again, I don't see much use for this "mod", other than it giving people a way to damage their vehicles.

 

[therealblinky]

Another Way to do it is Unplug the 4x4 Controll module. Its behind the Glove box. All you do is unplug 2 connectors and you have 2 wheel drive. Then all you have to do to get it back is Plug it back in. It would be good if you only need to use it once or twice.

 

[gijoecam]

That is a great way to destroy an otherwise perfectly good transfer case. This "mod" is not intended to allow for burnouts. In fact, it's pretty useless by itself. Now, if you have a way to disconnect the front diff from the wheels, then you could do the BWM as well, to prevent the front driveline from getting power.

Someone else suggested using it as a way to get 2wd LOW. Bad idea. This is gonna put some weird stress on the internals. It would kinda be like having to carry a 50lb bag of cement in one hand, and a feather in the other. You'd be "off balance".

Again, I don't see much use for this "mod", other than it giving people a way to damage their vehicles.

No harm whatsoever in using 2low. There's no 'balance' needed. The internals of the case make it a direct-drive through the t-case to the rear output shaft. Engaging the low range planetaries just adds a gear reduction, but the power flow is still straight through the case.

The transfer case clutch coil couples the front ouput to the rear output to get the power to the front wheels. (and if everything is rolling, there's little to no strain put on the case until the rears lose traction.)

Practical uses:

-Disconnect the front driveline for tight maneuvering in 4low. On a tight trail, it's a lot less hassle than shifting out of 4low, then back in when the going gets rough again. Simply flip the switch (on the fly), make the corner, then flip the switch back on (again, on the fly).

-Backing a trailer into a tight space, or maneuvering the Ex up a hill (or through soft ground) while trying to hitch up.

-Maneuvering on soft and/or slippery grass without tearing it up with the 4wd locked.

-Any other time when you need the gear reduction of low range, but not the driveline bind-up that comes from maneuvering in tight quarters.

If it does not save gas why do the mod? I would think it would save gas because the with out exact tire size because of tire pressure or wear there would be power lost when the clutch is cycling.

It does not save gas. If you have uneven-sized tires on it, you're doing something wrong to start with.