How to: 4x4 Troubleshooting guide

[dpacman]

wiring diagram needed for 4x4 control module

I have a 1992 ford explorer sport 4wd with a 5 speed.
and as seems so common the 4wd low does not work, i have checked everything listed in thse forums and then some, yes its in neutral, not moving, brake depressed, allready in 4wd hi, the 4x4 control module passed the self test, the actuator works and puts the tansfer case into and out of 4x4 hi ( i am assuming this wouldnt happen if the cam posistion sensor and or bump stop inside of it wasnt working) also checked the 4x4 low switch and wiring harness all the way from the switch to the module with an ohm meter, took the control module apart and verified the i was getting power, ground, contact with connectors was good and relays were working, they do when i put it in hi but nothing happens when pushing the 4x4 low button although i can verify the circuit is being closed from button one the dash all the way to the circuit traces on the control module.

at this point id like to find a diagram of the pin outs on the control module so i can start tracing the circuity to the safety switches but cant find it one anywhere. any help would be greatly appreciated.

 

[Tbars4]

...Welcome here...

..Try the first post of this thread...It probably is a cheap fix...
http://www.explorerforum.com/forums/showthread.php?t=123542

 

[pokodan]

4x4 low not working

do take apart your motor cause it aint a big deal and follow the thread above and put a new piece of rubber in place of your almost guaranteed broken plastic bumper stop and trim it to fit at the top of the stopper and hook it back up and it should work like a charm.p.s. instead of cutting the brown wire just undo the clip holder and dont lose it and put it back when your done. it aint hard.mine was the same -no low then no nothing-now it charges the dunes again.if only i had the money for stronger suspensionhmmmmmmmm.good luck

 

[MooseCat]

Turning 4x4 switch manually

I took off the shift motor today and turned the 4x4 switch knob on the transfer case manually. It turned relatively easily and my truck's 4x4 worked great. I've already rebuilt the shift motor following the instructions from:
http://www.explorerforum.com/forums/showthread.php?t=123542

Obviously I did it wrong. Any advice on what I should do?

MooseCat

 

[SevyDuce]

Can the gear housing cover be removed to access the stop bumper without removing the entire switch motor?

 

[DeRocha]

Can the gear housing cover be removed to access the stop bumper without removing the entire switch motor?

The Gear housing cover can be removed followed by the geared sensor to access the stop bumper.. However some members found they couldn't pull the geared sensor out because if felt bound. They ended up removing the sensor from the T-case (3 bolts) and the sensor popped right out.

 

[krautcan]

thanks for the very helpfull post re: guide to fixing 4x4 problems. i bought my 91 explorer at an auction for $250, knowing that was stuck in 4-lo. thanks to your post, i could diagnose the problem easily.the switch made the module click, module passed the self test, and i can hear the shift motor making a horrible racket underneath. going to look at it tommorow.

 

[RangerWade]

I'm having 4x4 problems and I am trying to test the system.My system seems dead,I have no relays clicking when I press on my dash switch.The self test passed on the computer (flashed 4 times).I replaced the dash switch but have the same results.What power/ground wires should I be measuring and where ??

 

[Carlo Diaz]

Dragging 4x4 once disengaged

Good day to all,
I have a 94 Explorer 4x4, the problem is that when i engage the 4x4 it engages perfectly and works perfectlt, the problem is when i go to 2wd again. I got to neutral and turn off the 4x4 lo and both lights turn off in the das and in the gauges. I can hear it disengage properly but when i start driving again i hear a hig pitched whinning on the right side of the truck. the faster i drive the louder it gets. i have to stop several timea dn engage and disengage the 4x4 until it goes away. Also, if i hit a bump, it will start to whine. Could somebody help me please???

Thanks beforehand,

Carlo Diaz

 

[DeRocha]

Good day to all,
I have a 94 Explorer 4x4, the problem is that when i engage the 4x4 it engages perfectly and works perfectlt, the problem is when i go to 2wd again. I got to neutral and turn off the 4x4 lo and both lights turn off in the das and in the gauges. I can hear it disengage properly but when i start driving again i hear a hig pitched whinning on the right side of the truck. the faster i drive the louder it gets. i have to stop several timea dn engage and disengage the 4x4 until it goes away. Also, if i hit a bump, it will start to whine. Could somebody help me please???

Thanks beforehand,

Carlo Diaz

The whine is caused by the automatic hub trying to engage. When were the automatic hubs last serviced and how much grease is in them. See the hub fixing/cleaning link in the 1st post.

 

[gsmaclean]

Actually, it's caused by the hubs trying to DISENGAGE. I had the exact same problem on my 94 Explorer. Fortunately it's not a mechanical problem - you just need to clean the hubs. It is relatively easy to fix.

Have a look at this post, I wrote it after I cleaned my hubs, and it details the process.

 

[sqhurt]

where is the reset button located at? is it the white thing by the red light? if thats it is it supposed to push in ? mine does not move but a hair thats why im asking..thats from pushing it in..

 

[krautcan]

test button

the white tab is the reset button, but you have to first disconnect the two harnesses on the left side of the box.

 

[krautcan]

4x4 module

my module self tests ok but only gives a millisecond spike of 12v to the shift motor.it has 12v + & - power to it, the switch gives it power but only 5.5 volts, but enough to activate the relays. i think the switch only delivers 5 volts so the relays don't burn out. if i jump the 4x4 input with direct battery power, the relays click and it still wont activate the shift motor anyway. i have jumped the shift motor from the pigtail harness at the module and it engages the t-case no prob. all the wiring looks good down to the motor,so it looks like i will spend $75.00 and a long lunch hour at the wreckers on the rez pulling out a module and gulping down mcnuggets on the way back. am i not the only one who goes to the junk yard for parts for my explorer and drools about what could be, or am i just sick?

 

[DeRocha]

Reminder:

The purpose of this thread is to consolidate troubleshooting information in one area so people can find the correct information quickly. It is not intended to become a huge run on thread where people ask questions as this would defeat it's purpose. Questions should be asked in other threads and any additional information deemed appropriate will be added to this one.

 

[abbott92]

Hey Great Thread! This is the reason why I joined this site, I was researching how to trouble shoot my 4x4 system when I found this site. It turns out it was the shift motor. The owner of the truck before me who has had it since new (I only bought the truck last year) and had NEVER USED the 4x4 system. He didn't even know how to engage it! My truck has 252,000 km and had never been off road! It turns out that after so many years of not being used, the motor is fried...no surprise there! So after reading this thread i gave the motor a couple whacks with a wrench and what do you know...IT WORKED ....and now it doesn't again So now i have a rebuild in my near future. Thanks for all the advice and pictures!!

 

[smtcapecod]

Kudos to the folks doing the rebuilds..but I just have to add some info in re: $300 price for the motor. Rockauto.com has them for +/1 $60 if you send back a core, $90 brand new...

 

[Tbars4]

...I seen you edited the first post.:shifty_ey ..Thanks for adding that info...:biggthump

 

[Four0Sport]

tbars.. i was hoping you posted in this thread so it would show up on the home page. i just went through 3 posts about 4wd lights not working and the t-case not engaging. if you didnt mean to.. you did anyway, high five!

 

[Tbars4]

...This thread is also in the "how to" in my signature...:biggthump

...And it seems to be the hot topic of the last 1/2 hour...3 threads asking the same thing..