Control Trac Question

[1996explorer4x4]

First off i want to say this is a great site! i never pst but always read...alot! ok well to the question.

ihave a 96 Explorer w/ control Trac 4 wheel drive. i was wondering if i could do the brown wire mod on it?? cause i hate the 4wd auto feature. when i put it in 4 wheel drive i want 4 wd. Thanks Alot

 

[TPLYNCH]

Sorry, but no. The brown wire mod only turns an Auto 4x4 into 2wd. You already have the 2wd. Nobody has come up with a solution to cause the Auto in '95-96 to be fully engaged as it is in 4Hi for the '97+ explorers

 

[jwrezz]

What's the difference in the T-case between 96 and under, and 97 and up? There are 4 selections on the switch, but does the T-case have 4 settings, or is it an electronic thing? Does it have to do w/ the earlier model's vacuum disconnect thing?

 

[gijoecam]

Sorry, but no. The brown wire mod only turns an Auto 4x4 into 2wd. You already have the 2wd. Nobody has come up with a solution to cause the Auto in '95-96 to be fully engaged as it is in 4Hi for the '97+ explorers

Incorrect. You can do the same brown wire mod as for the 97-up, but instead of cutting power to the transfer case, you APPLY power to the transfer case. The clutch works the same on both of them, but the GEM is programmed differently.

Break the brown wire. Use a SPDT switch rated for 30A. Run the center terminal to the brown wire leading to the transfer case. Connect the relay-side of the brown wire to one side of the switch. This position will allow the automatic 4wd to work as it normally would.

On the other terminal, wire-in a 30A relay triggered by a switched power source. This will prevent you from inadvertently leaving the clutch engaged overnight and killing the battery.

It will work. I've got mine connected like that currently.

If you connect to the brown wire somewhere downstream of the splice where the TOD relay meets the TCS relay, you will have complete control of the transfer case. 2wd high, 4wd high, 4wd low AND 2wd low all at the flick of the switch.

-Joe

-Joe

 

[jwrezz]

What do TOD, and TCS stand for? How would we (95-96) get 2wd low from this, if it is only an electrical modification as opposed to the vacuum disconnect mod? Thanx,

 

[gijoecam]

What do TOD, and TCS stand for? How would we (95-96) get 2wd low from this, if it is only an electrical modification as opposed to the vacuum disconnect mod? Thanx,

There's no need to mess with the Center-Axle Disconnect when you can simply force the transfer case to de-couple the driveshafts.

TOD is Torque On Demand. That's the one on the right side of the stereo opening.

The transfer case shift relay (TCS) is on the opposite corner down behind the GEM. (the TCS relay is hidden by the light in this pic... that's the GEM on the left)

Both relays have a brown wire that runs to the upper left hand corner of the opening where they are spliced in with a third brown wire that runs to the Transfer Case Clutch Coil.

The clutch coil is what locks the front and rear driveshafts together, and as far as I can tell, it works in a similar way the AC compressor clutch does.

You must cut the wire downstream of the splice.

If you cut the wire between the splice and the TOD relay, when you shift into 4low, the TCS relay will engage the clutch coil and lock the front and rear driveshafts together. By placing the switch in that particular wire, when you deactivate it, it forces the transfer case to disengage the front driveshaft, even though the planetary reduction gears are engaged for low range, hence you get the 2wd low range.

Now, in the case of the '95-96, in order to use the full-time 4wd, the selector switch must be set to 4 auto to engage the center-axle disconnect (followed by the switch used to force the full time transfer case engagement). If you wire it up the way I suggested above with the SPDT on-off-on switch, you can force the driveshafts to engage, but you will still need to rely on the GEM to engage the Center-axle disconnect. I suppose you could always replace the front axle with a later one to eliminate the CAD, but that could be more work than it's worth. Another option might be to adapt the 4x4posi-lock unit from the F-150 to fit the Explorer, but again, it may not be worth the effort.


On a completely unrelated note, I'd love to get my hands on an un-used transfer case to tear it apart and see what makes her tick. Anyone got one laying around they don't want?

-Joe

 

[jwrezz]

Ok, tell me if I'm wrong. My 3 way switch (2wd, 4auto, 4lo).
2wd is just that, no power going to the clutch coil

4 auto: the clutch coil gets power only when the TOD realy gets the signal to send the power to it

4 Lo: The TCS relay sends power to the clutch coil all the time.

If I snip the brown wire after the splice, no power gets to the clutch coil, if I put a switch in there I can turn OFF the power to the clutch coil when I want to.

If I apply 12v to the brown wire from where ever, I can force the clutch coil to engage. This would apparently work weather I have my switch set to 2wd or 4 auto? I would in effect have power going to the front drive shaft, but only when I put the switch to 4auto will the axle disconnect activate and give me true 4wd. If I take away that power, the TOD relay will then apply the 12v to the coil when it needs to.

Yeah, even I don't understand what I wrote now, but I think that's the jist if it. Thanx much GIJoe!