4wd Confusion

[Maxcaddy]

Great, now we're getting there

OK, I'll put 12V onto the brown in the morning, and see what happens.

Presumably if its a relay, I should be able to test for 12V going to it, to see if it's the TOD not switching the current, or the GEMS not supplying it ?

It's a floor change, I guess redesigning the colunm change for a build of 5,000 wasn't cost effective.

Cheers

Tony

 

[gijoecam]

Great, now we're getting there

OK, I'll put 12V onto the brown in the morning, and see what happens.

Presumably if its a relay, I should be able to test for 12V going to it, to see if it's the TOD not switching the current, or the GEMS not supplying it ?

It's a floor change, I guess redesigning the colunm change for a build of 5,000 wasn't cost effective.

Cheers

Tony

Umm, not quite... It's a solid state relay with a variable output... It's a relay in teh sense that it uses a small amount of current to control a large amount of current, but it's got no moving parts, and the output is not a solid steady output, it's a pulse-width-modulated output,as well as a PWM input from the GEM... I don't know of any way to test it.

-Joe

 

[Maxcaddy]

Well ................ getting to that unit was not easy and getting the connector off, no better

But once I got the connector off, I wired the 'brown wire' to the 'live' from the cigatette lighter and immediately blew the fuse

I then continuity checked the brown to earth, and it was 'earthing'.

I then wired the brown to earth at the TOD, and seperated the connector at the Transfer Case, and checked that I had a path to earth which I did. So the 'brown wire' from the TOD was 'intact'.

I then checked the brown from the other side of the connector (TC side) to earth and I have continuity. So the TC clutch has earthed itself which presumeably means its 'fubar'

I guess the power supplied to it has also either burnt out the TOD or the GEMS or both, although I can still get 4Low, but only to the rear wheels.

What's your prognosis ?

Cheers

Tony
(Happy yesterday, depressed today)

 

[gijoecam]

Well ................ getting to that unit was not easy and getting the connector off, no better

But once I got the connector off, I wired the 'brown wire' to the 'live' from the cigatette lighter and immediately blew the fuse

I then continuity checked the brown to earth, and it was 'earthing'.

I then wired the brown to earth at the TOD, and seperated the connector at the Transfer Case, and checked that I had a path to earth which I did. So the 'brown wire' from the TOD was 'intact'.

I then checked the brown from the other side of the connector (TC side) to earth and I have continuity. So the TC clutch has earthed itself which presumeably means its 'fubar'

I guess the power supplied to it has also either burnt out the TOD or the GEMS or both, although I can still get 4Low, but only to the rear wheels.

What's your prognosis ?

Cheers

Tony
(Happy yesterday, depressed today)

I would expect the t-case clutch coil to ground with very little resistance. The thing to check is the wiring with both ends disconnected to make sure it's not shorted to ground.

Let me double-check the schematic when I get to work... I was just thinking that it may have been shorting through the transfer case shift motor. You may need to find the splice I mentioned in the BWM thread... Follow the brown wire up into the loom in the dash there.... There should be a splice near the GEM somewhere before the brown wire heads down to the t-case.... We may need to isolate that from the system too... But let me check the schematics.

-Joe

 

[Maxcaddy]

Hi Joe, sorry you have lost me again

As I had continuity on my meter from the end of the (brown) wire which came out of the TC, to the outside of the TC itself, then surely any power supplied to that wire will give an instant 'short circuit' ? (and sparks like what happened at the cigarette lighter end)

Tony

 

[gijoecam]

Hi Joe, sorry you have lost me again

As I had continuity on my meter from the end of the (brown) wire which came out of the TC, to the outside of the TC itself, then surely any power supplied to that wire will give an instant 'short circuit' ? (and sparks like what happened at the cigarette lighter end)

Tony

Checked the schematics...

The transfer case clutch coil in your model year is grounded to the transfer case housing instead of using a separate wire to carry the power back to the battery's negative terminal (IIRC, they added a separate wire in '02 to feed the 'ground' signal back to the GEM). In your case, I would expect continuity between the brown wire at the transfer case and the transfer case housing itself with little to no resistance.

So, if you are checking for continuity between the brown wire at the t-case connector and the t-case housing, you will get a very low resistance reading. That's normal.

What we need to check for is a dead short between the torque on demand relay connector and the connector at the transfer case. Unplug the connector at the t-case and unplug the TOD relay. You should have continuity through the brown wire, and no connection between either end of the brown wire and a good chassis ground. Make sense?

If you have continuity to ground from either end, there is either a short in the brown wire somewhere, or the diode in the transfer case shift relay has gone bad. Unfortunately I can't tell you where that is located except that it's in the dash somewhere, connected to that 'other' leg of the brown wire, and the service manual only says that it's 'near the GEM' with no picture.

So, start with 'ringing-out' the brown wire to check for continuity and or a short circuit and we'll go from there...

 

[Maxcaddy]

OK done that and guess what, with the brown wire disconnected at the TOD and at the TC joint, I still get continuity to earth from either end

So somewhere between those 2 ends its earthing out.

Now the problem is that with the TOD on the left and the GEMS on the right, with all the other wires to the fascia controls, Radio, Auto ride height etc, etc, there's more spagetti than in a clint Eastwood Western

I will check as best as I can the path from the TOD connector to find the splice and any other take offs, but that's going to take a lttle time.

2 thoughts for your advice please.............

(1) If I can find a good GEMS & TOD from a UK breaker shall I get them and hope it cures the problem ?

(2) Can I connect a 12V feed to the TC side of the TC connector (brown pin)to power the clutch, to know that it will work once (if and when) I've sorted the electronics ?

Regards

Tony

 

[gijoecam]

Then I would agree, either you have a wire that's chafed through someplace it shouldn't be, or as I mentioned before, teh transfer case shift relay diode has gone bad and it's allowing the signal to ground through it. Unplugging the shift relay would isolate those two (if you can find it, of course). If you reconnect everything and try switching from high to low range and back a few times with the dash opened up, you might be able to track it by following the sound... Wish I could be more help there...

I don't think the GEM or the TOD relay are the issue. I think you're right in that it's a dead short to ground from the brown wire that shouldn't be there.

Now, if it was my truck, I would do the BWM as you suggest, making sure to make the connection downstream of the splice (on yours, I suspect that splice will be found in almost the same place mine was, but on yours it'll be up behind the ARC module instead of the GEM). At least at that point you would have full manual control over the transfer case lockup. You would lose the automatic control from the system, but you didn't have that to start with (that's what opened-up this can of worms in the first place!!).

But before you do that, I would suggest manually applying power to the transfer case clutch coil at the transfer case itself to verify that the clutch locks the transfer case the way it should. You should be able to do that with a couple of jumper wires and a paper clip if necessary to probe the connector. That'll help ensure that at the very least, the t-case works.

I'd still want to know where the wiring issue lies though... It would drive me bonkers not knowing where the original problem started from...

Getting closer!!

 

[Maxcaddy]

Yeah getting closer by 2 steps forward and 1 step back

Transfer Case Shift Relay , just as I thought I was starting to understand the system, you throw in another unit. :scratch:

Would you (or any other kind soul) guide me to photo of this TCSR so at least I know what I'm looking for.

Many thanks

Tony

 

[gijoecam]

When I get home, I'll PDF the schematic of the system and post it on my yahoo account... maybe that'll help clarify why that's a concern... It'll probably make more sense then...

-Joe

 

[Maxcaddy]

Hey some excellant news at last. When I put 12V onto the brown wire at the multipin connector down on the Transfer Case, the front prop shaft locks

So (fingers crossed) it seems to me my TC is OK, and as you said, its in the electronics where its wrong.

My fall back position is to break the brown wire somewhere downstream of the dash, and put a new wire in up to a new live switch. Which )in conjunctiion which the existing switch) will give me 2WD, 4H and 4L instead of the 2H and 2L which I have now. Although I can't really see a convenient place to put one, as all the existing places already have switches and controls fitted.

I did look at the existing Auto/4H/4L switch which has 4 wires going to it, but there's only continuity between 2 of the pins irrespective of switch postion, and it's permanently powered by 5V. So presumeably it's another of those fancy solid state devices which will not lend itself to being played with.

Trying to get in to the dash to seperate those wires is a real game for me, so the new wire is probably easier.

I don't know how to access your PDF on your Yahoo account, but I have found this diagram off of an old thread.

Assuming its the right one, any advice on where the Transfer Case Shift Relay is hidden, or infact what it looks like, would be very welcomed.

Regards

Tony

 

[gijoecam]

Hey some excellant news at last. When I put 12V onto the brown wire at the multipin connector down on the Transfer Case, the front prop shaft locks

So (fingers crossed) it seems to me my TC is OK, and as you said, its in the electronics where its wrong.

My fall back position is to break the brown wire somewhere downstream of the dash, and put a new wire in up to a new live switch. Which )in conjunctiion which the existing switch) will give me 2WD, 4H and 4L instead of the 2H and 2L which I have now. Although I can't really see a convenient place to put one, as all the existing places already have switches and controls fitted.

I did look at the existing Auto/4H/4L switch which has 4 wires going to it, but there's only continuity between 2 of the pins irrespective of switch postion, and it's permanently powered by 5V. So presumeably it's another of those fancy solid state devices which will not lend itself to being played with.

Trying to get in to the dash to seperate those wires is a real game for me, so the new wire is probably easier.

I don't know how to access your PDF on your Yahoo account, but I have found this diagram off of an old thread.

Assuming its the right one, any advice on where the Transfer Case Shift Relay is hidden, or infact what it looks like, would be very welcomed.

Regards

Tony

That would be the schematic I was going for... Let me get home again and make a few notes that'll help out...

 

[gijoecam]

This is the way it *should* work:

If the diode in the TCS relay fails, power could flow this way:

That's why I was hoping you could disconnect the shift relay from the system to 'ring-out' the brown wire. That would tell us if the shift relay was bad, or if the brown wire was bad. I think it's down to those two possibilities. It's the only two things that makes sense with the TOD relay and the shift motor connector disconnected.

Make sense?

 

[Maxcaddy]

Excellant guide Joe, many thanks for checking it through, I thought that was it, until.........

I tried to separate the 'brown' wires, but on mine the splice is up behind the fibreglass air vent piece, and to get to it will mean stripping the dash out.

But I believe I have found the Transfer Case Shift relay here ?

Is this the little sucker ?

I rechecked that the 'brown' wire from the TOD was still earthing. I then disconnected the the TCSR and retested the TOD brown to earth, and I still had a path to earth

I then tested from the TCSR connector to earth, and had a path, and from the TOD connector to the TCSR connector, and had continuity.



Therefore I suggest I must have a chafed (or similar) brown wire somewhere

If I'm on the right track, the only thing I can think of is that a while ago I fitted a CD multichanger under the rear left side seat and run the wires under the plastic door tread up the corner of the footwell (behind the plastic panelling). So it could be along there that its caught the Brown.

If I can't find where the problem is, I'm tempted to cut the Brown at the TOD, TCSR and where it comes through the floor, and run a new wire joining them together.

What do you think ?

Ciao

Tony

 

[gijoecam]

Excellant guide Joe, many thanks for checking it through, I thought that was it, until.........

I tried to separate the 'brown' wires, but on mine the splice is up behind the fibreglass air vent piece, and to get to it will mean stripping the dash out.

But I believe I have found the Transfer Case Shift relay here ?

Is this the little sucker ?

At a glance, I can't tell you... I've never actually seen one before. What I can tell you is that the clicking on mine when I shift from 4high to 4low comes from that general area, so it would make sense. The way to confirm it would be to check the wire colors. There should be eight wires whose colors match the schematic you linked to. (or most of them... being an export, if one wire was off, I'd call it close enough). Most important, one of those wires should be the brown one (which it is) and it should ring to the brown wire at the TOD relay connector as well. If that all matches-up, I'd say you found it.

I rechecked that the 'brown' wire from the TOD was still earthing. I then disconnected the the TCSR and retested the TOD brown to earth, and I still had a path to earth

I then tested from the TCSR connector to earth, and had a path, and from the TOD connector to the TCSR connector, and had continuity.



Therefore I suggest I must have a chafed (or similar) brown wire somewhere

If I'm on the right track, the only thing I can think of is that a while ago I fitted a CD multichanger under the rear left side seat and run the wires under the plastic door tread up the corner of the footwell (behind the plastic panelling). So it could be along there that its caught the Brown.

Aaaah, and the rest of teh story comes out....

If I can't find where the problem is, I'm tempted to cut the Brown at the TOD, TCSR and where it comes through the floor, and run a new wire joining them together.

What do you think ?

Ciao

Tony

I think you finally got the wiring figured out! I would agree you're definitely on the right path. I know that the brown wire runs through the loom underneath the driver's side--- I mean passenger side for the RHD vehicles--- kick panel. If you look at the brown wire mod thread, that's where a lot of people splice in the switch for it. If you pulled the kick panel off there when installing the CD changer, I'd bet the problem is somewhere in there. Here's what I'd do:

Pull the left hand side scuff plate off (I forget what's involved, but since you've done it before, I'm sure you can manage). Inspect the brown wire for any obvious signs of damage. If there are no obvious signs of damage, cut the wire inside the vehicle (before it goes through the floor). Now, check both halves of the wire for a ground path with everything still disconnected. That should tell you whether the broken wire is between the dash and the door, or between the door and the transfer case.

Nex, I would run a bypass wire around the damaged section... if the damage is inside the cabin somewhere, you'll need to find that splice so you know you are downstream of it. You'll need to cut it there and see if the short to ground is in the dash or between the dash and the door. (again, not easy given the route your wiring takes through the dash) If the damage is between the door jamb and the t-case, simply run a new wire around it. You should be able to run it right on the loom that's there.... getting it through the floor could be a challenge, but not too difficult.

Either way, I'd install the switch for the brown wire mod anyways... Since you've got everything apart, you've already done 95% of the work anyhow.

Make sense??

-Joe

 

[Maxcaddy]

Here's what I'd do:

Pull the left hand side scuff plate off (I forget what's involved, but since you've done it before, I'm sure you can manage). Inspect the brown wire for any obvious signs of damage. If there are no obvious signs of damage, cut the wire inside the vehicle (before it goes through the floor). Now, check both halves of the wire for a ground path with everything still disconnected. That should tell you whether the broken wire is between the dash and the door, or between the door and the transfer case.

Next, I would run a bypass wire around the damaged section... if the damage is inside the cabin somewhere, you'll need to find that splice so you know you are downstream of it. You'll need to cut it there and see if the short to ground is in the dash or between the dash and the door. (again, not easy given the route your wiring takes through the dash) If the damage is between the door jamb and the t-case, simply run a new wire around it. You should be able to run it right on the loom that's there.... getting it through the floor could be a challenge, but not too difficult.

Either way, I'd install the switch for the brown wire mod anyways... Since you've got everything apart, you've already done 95% of the work anyhow.

Make sense??

-Joe

Nooooo, if anything were that easy I'd already done it

I pulled the left hand side scuff plate off and there's a giant stash of wires and connectors, but no brown wire

I pulled the cover strip off the bottom of the door gap and prised up the top of the conduit and examined the wires just before the seat. The bundle is about an 1" thick but although I found 3 black wires, there was no brown.

OK thought I, lets start from the other end, so the passenger seat (drivers to you lot) came out, and the carpet up (bit wet under the passengers footwell but I guess that's typical) and found the bundle that went through the floor to the TC. Checked underneath that I was on the right bundle, as there's another one there, but that runs to the rear along the chassis rail.

Stripped back the tape under the seat and found the brown

Undid the tape where that bundle is joined to the main cable run along the door edge .......and found the brown wire goes backwards towards the rear :frustrate

Pulled the rear conduit apart and can see that it splits and some go up the door frame, and some continue under the rear seats.

Getting dark and fed up by now, so I'll look again in the morning. Only hope I can get it all back together as there's wires, and connectors, and units, and trim everywhere :scratch:

The only good news is that 6 of the 8 wires match their colour code, so I'm fairly sure that grey unit is the TCSR.

Ciao

Tony

 

[gijoecam]

You might have more luck starting at the transfer case and following it back into the cab... You right-hand drive clowns have got everything outta whack on this thing!! Unfortunately none of my schematics show squat for any of the export models, let-alone a right-hand drive model. Can't you just drive on the right side of the road like the rest of the civilized northern hemisphere??

Just playin'...

 

[Maxcaddy]

.
.
I'm getting worried now, I've seen cars more intact than mine at the local breakers

So, I followed the wire out from the seat along the rear door sill, past my extremely neat and innocent CD fixing.....

Then along under the back seats upto the drivers (passengers for you LHD) footwell where it goes into 2 connectors. Here it goes wrong because I have this bolt stuck into one connector

and worse still, there's 2 browns in the other connector

So somewhere around the car its picked up another brown.

Seems I'm going to have to completely strip the tape of all the wires all the way around to see where this new browns come from.

This will not defeat me. We will fight them on the beaches.............

Btw, I understand that RHD went back to the medieval days of chivalry, when two horsemen approached each other they would each keep to the left hand side of the track, so if it turned nasty they (usually right handed) could draw their swords and get stuck in quicker. I guess that was a few years before Columbus got lost :bsnicker: Japanese Samurai obviously did the same.

Ciao

Tony

 

[Maxcaddy]

Hi Joe, I'm back......

I've now done so much, I'm not certain of what worked when, and with what unit disconnected

As I have stipped out the inside, seats, carpets, etc, and that all internal wires have been un-taped, I come to the following conclusions.............

The wiring from the dashboard area down to the TC case clutch is intact.

At one stage when it was still apart, supplying 12V to either the TOD brown or TCSR brown locked the TC clutch, although the GEMS top connector was off at the time in order to move the GEMS out of the way. I don't know what the GEMS top connector powers, but the internal lights were inoperative.

When wired back together there is something magical happening possibly in the TCSR or the GEMS, that is 'grounding' the path.

With the ignition on and 4High selected (and the TC connector underneath apart) the brown wire is earth'd.

So I believe my choices are :

1. Change the TCSR, TOD and GEMS (in that order) to see if that works.

2. To wire a secondary live switched feed to the TC clutch (variation on the brown wire mod).

The ideal place for my brown wire switch is on the centre console, but I can't see how this comes out without breaking it (my one houses the gearchange and the handbrake) ???

Anymore thoughts ?

Ciao

Tony

 

[gijoecam]

The wiring from the dashboard area down to the TC case clutch is intact.

At one stage when it was still apart, supplying 12V to either the TOD brown or TCSR brown locked the TC clutch, although the GEMS top connector was off at the time in order to move the GEMS out of the way. I don't know what the GEMS top connector powers, but the internal lights were inoperative.

So, with the transfer case end plugged in, and both the TCS and TOD relays disconnected, power applied locks the clutch, correct?

When wired back together there is something magical happening possibly in the TCSR or the GEMS, that is 'grounding' the path.

But, if my memory serves from your earlier testing, with the TOD relay disconnected and both the TCS and t-case connected, it was grounded, right? If so, then I would say start with the TCS relay. That seems to be the most likely culprit in my opinion.

So I believe my choices are :

1. Change the TCSR, TOD and GEMS (in that order) to see if that works.

2. To wire a secondary live switched feed to the TC clutch (variation on the brown wire mod).

The ideal place for my brown wire switch is on the centre console, but I can't see how this comes out without breaking it (my one houses the gearchange and the handbrake) ???

Anymore thoughts ?

Ciao

Tony

Don't forget choice 3: 1 and 2. However, I'd bet that the problem is in the TCS relay. If you look at the most recent test, it points in that direction. I'd start there. (not to mention it's a fraction of the price of the GEM)

Having never laid hands on a LHD Explorer, I'm taking a guess here... I'd guess that the handle on the shifter comes off somehow (a hidden screw or clip, maybe?) then the trim around it will usually pop off (spring clips... give it a tug). From there? I don't know... but that should get you enough access to see more. If you take some pics of the console from all the angles you can, I might be able to make an educated guess, but that's all it would be. A local dealership might be able to pull the prints for it for you to give you a better idea...

-Joe