4x4 problems

[96expsport]

my explorer was stuck in 2 wheel drive but it was in low gear the local ford garage said it could be a 4wd shift control module behind the radio and heater controls and theres to modules can anyone tell me which one is the one i need to replace or can anyone give me come advice

 

[Ray Lobato]

Sounds like your shift motor will not go back to hi.
The transfer case only has 3 positions, HI, Neutral, and LO.
The shift motor will switch between HI and LO.
You can take the shift motor off, move the transfercase to hi, move the shift motor to the hi position and put it back on. Then remove the ground lead from the battery for about 5 minutes and put it back on. This should reset everything to the normal mode.
You can then try and go into 4LO and see if it will move. it is does and you can get back into HI, it just neede to be reset. If it doesn't move into 4LO, you have a problem with either a blown fuse or the shift motor needs to be cleaned or replaced. It could be the shift module, but it's not likely. Usually the shift motor will have problems before the module.
Give this a try and let us know how it went. I'm sure that we can get this fixed.

Oh! and welcome to the site.

 

[96expsport]

thanks

thanks for the help but we already pulled the motor off and it still does it do u have any ideas what else it could be

 

[gijoecam]

You'll need to check the connector at the motor to see if it's the module or the motor. I'd mirror what Ray said: Generally the motor gets toasted long before the module, but there's no way to know for sure. If you take the motor off, re-set the position, and plug it back in and it moves, I'd probably side with the dealership on this one. It's rare, but it happens. A new motor isn't a difficult job, or expensive if you get one from a salvage yard. Might even want to see if anyone around here that's done a manual t-case swap has one laying around they'd be willing to part with. It can't hurt to ask.

-Joe

 

[Ray Lobato]

thanks for the help but we already pulled the motor off and it still does it do u have any ideas what else it could be

What do you mean by it still does it? You Mean that it will go into 4LO but won't go back to HI? Did you move it back to HI and It went to LO? Please explain.

 

[96expsport]

ok it doesnt go into 4 hi or 4 lo when you turn the switch but when u go down the road the rear whells will lock into low and it wont come out

 

[gijoecam]

I'd say that it's the transfer case shift relay or something in the GEM calling for the shift at the wrong time. The motor itself has no power to it statically, so it's not going to spontaneously move by itself. It must be receiving power to make the low-high or high-low shift, and that power is usually fed from the fuse, through the relay, and the trigger for the shift comes when the GEM grounds the relay.

Soooo.... I see a few different possibilities:

-The first is a bad GEM incorrectly calling for a shift.
-The second is a short to ground in the wiring that triggers the high-->low shift. Those two wires are in the BR/PK and GY wires that run between the transfer case shift relay and the GEM. I'm not sure which of the two triggers the high-->low shift offhand.... somebody should be able to tell us.
-Third is (and this is a VERY remote possibility) is a failed transfer case shift relay, AND a bad diode in the relay. That *could* potentially allow a back-feed of power from the Torque-On-Demand relay through the infamous brown wire to the transfer case shift relay, through the shift motor. The odds of both parts of that relay failing are VERY remote IMHO.

As a temporary fix, you can remove the motor, turn the shift shaft back to the high position, re-set the motor by applying power to pins #14 and 15 in the plug on the motor (orange and yellow wires) until the motor is in the proper position, and then reinstalling the motor, but leave it un-plugged. With the connector unplugged, the motor can't move. If you still experience the problem, then it's a mechanical problem with the transfer case, for sure, but I doubt that's the case here.

Let us know what you find.

-Joe

 

[96expsport]

ok its doesnt go into 4 lo or 4 hi it just locks into low gear when i start it and go to pull away it is in low so we put it on a lift but only the rear wheels are turning so its in low gear and 2 wheel drive but we cant find any voltage drops or any shorts and the shift motor is new and the 4wd swith is new but we still havent found anything that could be causing it

 

[gijoecam]

It's really quite simple: Either there's something telling the motor to move and it's turning the shift fork, or the transfer case itself is mechanically broken, allowing the low range gears to slide in and engage. Checking the shift shaft position is the simplest thing to do, and you do that WITHOUT the motor in place. If it's in low range, but the shift shaft is in 2wd, it's the t-case. If you take the motor off, and find the motor and shift shaft are in the low range position, something told it to shift, and it's electrical.