no air through vents and 4WD on front tires won't disengage.

[rosrooster]

Air is only blowing through my defroster and I can't get the 4WD to disengage from the front tires.

I'm suspecting a vacuum issue somewhere but have not found any leaks. I did trace the vacuum lines up to the side of something by the brake master cylinder, and when i wiggle and pull that out the engine almost dies and there is a liquid, that i assume is gas because of the smell, that comes out of there, but then my vents start working until the vehicle is restarted. I checked the actuator behind the glove box and that is functioning (not broken).

I searched and I can't find what actually controls locking in the hubs on a 2002 for explorer. Seems like it could be a vacuum line to each hub that controls it, or a single vacuum actuator that locks both in. Also read it could be PCV valve, EGR valve, IAC that could be causing this.

 

[J_C]

Welcome to the forum!

These are probably unrelated, yes a vac leak and I'd pull the HVAC control panel out of the dash to check vac there. What you stated about pulling a line off and seeing a gas-like liquid doesn't ring any bells. Can you take some pictures? Is it possibly the evap line from the gas tank?

Does your Eddie Bauer have the 4.6L and AWD or 4.0L and 4WD? The 4WD is not vac actuated, uses an electromagnetic clutch in the transfer case. The hubs are always connected to live front CV axles, live diff. and axle to the transfer case.

None of the things you listed can affect the 4WD. If it's actually AWD, they are supposed to be engaged, but if 4WD, you might have some speed sensor problem causing the system to think you're always losing traction. I'd get a scan tool capable of live data, of course scan for trouble codes but also look at all the speed sensor readings in realtime while driving. Not much point getting into more detail until we're sure you have the part time auto-4WD version. If you do, for the time being you could disable that by cutting the brown wire from the 4WD module next to the radio in the dash, to the transfer case, or of course unplug it but I can't predict any potential errors codes that might come from unplugging it.

 

[rosrooster]

It is the 4.0L AWD.

I've attached a screenshot of the thing that I unplugged that gets the vents working again.

Do you have more detail on "cutting the brown wire from the 4WD module next to the radio in the dash"?

 

[J_C]

I can't make out what that plugs into, picture too blurry and lighting bad.

Search the forum for "brown wire mod" and it will provide several topics.

 

[rosrooster]

Well last night I tried a couple of things to get the front wheels to disengage, but none of them worked.

I tried pulling fuse 12 from the fuse panel under the drivers side dash.

I also tried disconnecting the 4x4 control module behind the glove compartment.

I did research the brown wire mod, and found that it doesn't really pertain to the 3rd generation explorers(correct me if I'm wrong, and please supply link to instructions).

Also ordered EGR components to see if that will help with vents. EGR Valve, EGR Valve Pressure Feedback Sensor, and EGR Valve Vacuum Modulator. I'll also replace the PCV valve.

Sometimes I feel like I'm slowly rebuilding this thing one piece at a time.

 

[J_C]

BWM is a thing for 3rd gen too. This is probably the most populated topic:

BWM Brown Wire Mod 3rd Gen

I know this has been posted before, but here is the post with pics and a better title for those searching. 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. Give your self about 2-3...

www.explorerforum.com

I am not there seeing what you are trying so please forgive if this is a dumb question, but after you disconnected the 4x4 control module, what evidence did you have that the front wheels were still engaged?

Are they binding while driving, while making turns? If they are engaged and there's 12V continuous on the control wire to activate the 4WD clutch, then you have an electrical problem. If the control wire is not receiving power, then your clutch is stuck locked up in the transfer case and may need TC rebuild. Has the fluid in the TC been changed in the last few years? If not, that's something I'd do as it is regular maintenance anyway.

 

[rosrooster]

Binding while making turns is my biggest complaint.

I have not changed the fluid in the TC, I'll try that tonight. Do you know off hand what fluid to use and how much?

Should I be able to just cut the brown wire and see if the issue goes away?

 

[J_C]

If the brown wire is going to the 4x4 module you unplugged, so it is impossible for it to be getting 12V, then there is nothing to gain cutting it. I mean if there's not 12V on it, it's just as non-functioning as if it were cut. I just don't want you to cut it and have no difference but sure, you can just cut it then make sure the live end of the cut is insulated so it doesn't short out on anything.

This is unless the front wheels aren't always engaged, that it take making a turn for the speed sensor difference to be enough to engage 4WD.

Transfer case fluid, if it's the BW 4405 like my '98, it takes 1.5qt. Either way, Motorcraft XL-12 Transfer Case fluid, or something like Valvoline 855459 Transfer Case Fluid. Do not use Mercon V or LV. I'm not sure if the 4406 and thereafter take a little more like a whole 2qts. Get 2qts and fill till it reaches the hole.

 

[rosrooster]

So I either found a problem or created a new problem while changing the transfer case fluid. After I drained the old fluid and was in the process of putting in the new fluid i noticed that it was leaking out right next to the drain plug on the bottom of the transfer case. After looking closer I noticed that there was a small crack in the metal next to the drain plug, after some researching it sounds like i could have easily done this myself by overtightening the drain plug.

So my question now is since I know there is a crack near the drain plug that is leaking fluid and the vehicle is not disengaging from 4wd is my best bet to just replace the transfer case and should that resolve my issue with the 4wd not disengaging?

 

[J_C]

How much fluid did you get out? If it didn't look like a full load, possibly low fluid was causing your problem? I'm not suggesting that all it needs now is a full fill of fluid, rather that it probably burnt up the clutch pack if ran low, or as you stated, might be new damage in addition to the pre-existing problem.

Yes you either need to try to patch (JBWeld epoxy = temporary, or TIG weld = "maybe" permanent) the crack, and I don't know how much success you might have with that, or replace the T-case.

I don't know if it will resolve your problem, depends on whether it was electrical or mechanical. If mechanical then there's a good/probable chance it will. If the clutch in it isn't getting 12V when stuck in 4WD, this does suggest it's mechanical.

 

[rosrooster]

I got about 1.5 quarts of fluid out. I picked up a used transfer case, going to try swapping that out this week and see if that solves the issue

 

[LMHmedchem]

Sometimes I feel like I'm slowly rebuilding this thing one piece at a time.

That is a very common feeling around here.

I am in a constant battle to replace things before they rust away to nothing and fall off on their own.

LMHmedchem