4x4 wont engage, light comes on

[gabrielkeeven]

I have a 99 explorer xlt 4.0l sohc

The light for the 4x4 will come on but it will not engage. When the front is lifted and axle turned by hand with car off, the wheels spin opposite. When ignition is on and 4x4 is turned from auto to high, light turns on but the front axle still rotates freely.

I understand this to be a transfer case malfunction or some electrical problem. Is that correct? If so, what are the next steps to diagnosing the specific problem?

If this has been covered already please just send me in the right direction. Thanks!

 

[XLTrunner]

There seems to be a number of owners with 4x4 shift problems lately. I went through my own transfer case problem this past Spring and found this old thread very helpful in understanding just how the Borg Warner 4405 works. For those with problems, it's worth reviewing to get a general understanding of the various components (both internal and external) that can affect it's ability to function correctly. For those who's truck won't engage into 4x4, a likely suspect would be the shift motor itself. Or, could be the wiring harness connector underneath next to the shift motor...or, famous Brown wire that goes into the t.c. case that's corroded/broken.

http://www.explorerforum.com/forums/showthread.php?t=182071

 

[gabrielkeeven]

Thanks for that link XLTrunner, very insightful

after reviewing this article https://www.explorerforum.com/forums/showthread.php?t=203441

I thought that the shift motor is not responsible for locking the transfer case? And replacing the shift motor wont fix my problem?

When in Auto 4x4, I can press the brake and gas at the same time, when the back wheels start to slip, the front wheels do nothing different. Leading me to assume the transfer case is the culprit, correct?

I will check the wiring today to see if anything sticks out. Is there a voltage test I can do with the wiring to test for shorts?

 

[drdoom]

Correct the shift motor only changes the range, front axle engagement is controlled electronically. So look for electrical faults, make sure someone hasn't done a brown wire mod, check fuses, test the GEM if necessary. Find the 4wd troubleshooting thread here, lots of info. Personally I would first get a reading on the brown wire entering the transfer case, you should have around 6V DC when in 4x4 HIGH. If you don't have that check connections fuses etc. Also I don't understand the test protocol you are using, I have never heard of testing in such a manner. Better to raise entire vehicle and check with engine running and in drive to see if front is engaging, be safe of course.

 

[gabrielkeeven]

Which thread are you referring to?

I tried testing the brown wire where it enters the transfer case. I had no voltage there. Which fuses should I check? What would I test next?

 

[Turdle]

Look in the driver compartment, maybe under the seat for an installed switch. This switch is a common modification to achieve true 2wd and supposedly save fuel. Many explorers have this installed by the previous owner. Brown wire mod is the term to search for.

Also, I might be wrong but something tells me the ABS signals the transfer case to actually drive the front wheels. Do you have any ABS issues? ABS light on?

Does the ABS light illuminate when you first switch the key on during the cluster light check?

 

[gabrielkeeven]

I doubt it was modified but i will look around. Ive owned it for 4 years now and the last owner was an older guy.

The ABS light comes on when starting the car but goes off like normal after a second.

I know for a fact the 4wd worked when I first purchased it. I found out the hard way it wasnt working anymore when I tired to go up a snowy driveway two winters ago.

Im heading to Colorado soon and would love for it to be working again. Any/ all help is much appreciated