4wd Confusion

[Maxcaddy]

Thanks Joe, sorry its taken me few days, as its not stopped raining.

Anyway I thought I was on the T/case as its the last unit on the transmission, and it has the front prop shaft going out from it. The 2 pics are the connector and the wires into the case that I can see. Am I looking at the right thing ?, and if so, is the 'brown wire' one of those in the multi plug ?

The noise I was listening for was some kind of engagment when 4High is selected, as I expected there would be a dog gear or moving sleeve on a splined shaft etc to connect the 'drive' to the front propshaft. I understood that the T/case is chain driven, so presumeably either the chain is permanently moving and 4High connects the front prop, or, its that the chain drive starts driving from the main output (rear propshaft) shaft when 4High is switched ? Hence I was expecting some kind of action

Thanks for your support

Tony

 

[gijoecam]

The second set of pics is the t-case. I am having a brain fart at the moment as to where specifically the brown wire runs through the case... I'll have to take another look at mine, but it's raining outside right now. If my memory serves, it's sort of high on the passenger side of the driveshaft, but don't quote me on that one...

The wire you want is in the connector in the first pic... As viewed in that pic, the brown wire is the front left wire. Immediately to its right is the yellow wire.

With a live front axle as you have on your Ex, the front half of the drivetrain rotates at all times. That's the way the system is able to instantaneously lock the front end when it detects rear wheel spin, without grenading the t-case. The only thing that moves when shifting to 4high are the electrons running through the magnet in the clutch. Yes, the apply cam moves minutely, driving the ball-ramp assembly into the locked position, but the movement is miniscule.

-Joe

 

[Maxcaddy]

OK, the 'famous' brown wire is presumeably one of the two wires going to the rusty black solenoid. I guess the yellow is the other ? I will check the brown for 12V asap.

I'm still confused by the way the system works. If "the front half of the drivetrain rotates at all times" then presumably there are no 'free wheeling hubs' so the front prop is driven by the front wheels turning. Then the "magnet in the clutch" is presumeably engaged automatically in 4auto or constantly engaged in 4high to drive both prop shafts ? If this is how it works, does the rear diff also lock and drive both rear wheels ?

I really don't mean to be dim but I have looked on this site for a description of the way the 4x4 works, but to no avail. Although there is an excellant write up on here for stripping the Transfer Box and rebuilding it (assuming mine's a 4405), which I hope I don't have to do

Many thanks

Tony

 

[gijoecam]

OK, the 'famous' brown wire is presumeably one of the two wires going to the rusty black solenoid. I guess the yellow is the other ? I will check the brown for 12V asap.

What rusty black solenoid are you talking about? In the pics you posted, there is ONE and ONLY one brown wire, and it's BROWN, not yellow, not orange, not something with a something-stripe, it's BROWN.

I'm still confused by the way the system works. If "the front half of the drivetrain rotates at all times" then presumably there are no 'free wheeling hubs' so the front prop is driven by the front wheels turning.

Correct.

Then the "magnet in the clutch" is presumeably engaged automatically in 4auto or constantly engaged in 4high to drive both prop shafts ?

Correct again. Two for two.

If this is how it works, does the rear diff also lock and drive both rear wheels ?

BRRRRRRRRRRPBT!!!! {big red X flashes on the screen from Family Feud as Richard Dawson kisses your wife}

I really don't mean to be dim but I have looked on this site for a description of the way the 4x4 works, but to no avail. Although there is an excellant write up on here for stripping the Transfer Box and rebuilding it (assuming mine's a 4405), which I hope I don't have to do

Many thanks

Tony

Re-read the first part of the brown wire mod thread. I did a pretty simple explanation of how the system works. Think of it as an Air Conditioner Clutch that momentarily locks the front and rear output shafts when necessary in 4auto, and keeps them locked in 4high.

-Joe

 

[Maxcaddy]

Now keep calm Joe ,

I've re-read the BWM thread, and it made much more sense than the first time I read it, other than ..... does it work on a V8 AWD model (hey I'm joking)

The problem is that I don't have a Brown Wire !!!!!!!!!.

If its the wire on this pic

i.e the wire coming out of the 3 inch diameter black round thingy/solenoid/motor/whatever (along with a yellow wire), then my one is definitly ORANGE, and is wired to the multiconnector like so.

The other wires as best as I can make out are 5 going to a unit next to the black one which has a grey plastic cover (this includes the thin Orange and the {only} brown with a stripe). There are 3 wires going to the casing where the main propshaft is, and a black wire that goes through the case like these shown here....

If the wire which I say is Orange is the one known as the 'usual' Brown wire, this could be because my Explorer is an 'export' UK RHD version ???

Now, the good news is that there is not 12V going to my Orange wire. The engine was running in 'P' and 4High selected and lit, in fact I didn't have 12V coming out of any of the pins ???

If I've done the right thing, this presumably means the source of the 12V isn't supplying, so what's the next unit downline that supplies the 12 volts ?

Many thanks

tony

 

[gijoecam]

The brown wire is right there..... Wait until I get home tonight and can do a screen shot or two... I'll be home around 5. Update to follow shortly thereafter...

 

[gijoecam]

You have a brown wire, just like all the second-gen automatic-4wd's made from 1995-2001. It's right there in front of your face.

Here are the follow-up pics I promised:

 

[Hitchhikingmike]

You have a brown wire, just like all the second-gen automatic-4wd's made from 1995-2001. It's right there in front of your face.

Here are the follow-up pics I promised:

lol

 

[Maxcaddy]

OK, I'm with you now, so that one is the brown wire , It looked to me to be black, but with my eyes, I was clearly wrong :notworthy.

Now that's sorted I've checked it again, and it still doesn't give 12V when the engine was running in 'P' and 4High was selected and lit.

So what's next ? as the the source of the 12V isn't supplying, what's the next unit downline that supplies the BROWN wire with 12 volts ?.

Many thanks again

Tony


P.S. to 'Hitchhikingmike', thank you for your meaningful valued contribution.

 

[gijoecam]

If the light comes on, then we have an electrical issue further up-stream... I'm going to be busy the rest of the weekend, so it'll probably be monday before I can pull up the schematics and see...

Off-hand, does 4auto work? (It shouldn't)...

 

[Maxcaddy]

Thanks for your help Joe.

I have tried to see/understand the wiring details from the 2 books I have (Chilton Ranger/Explorer/Mountaineer 91 -99, and Haynes Explorer 1991 thru 2001) but the detail isn't there or I can't find it In fact the detail they go into on the Tansfer Case is less than 1% of what I have learnt on here from you

I understand that the total number of Explorers sold in the UK (1998-2002) was less than 5000 and these were all 'Export RHD' with presumably different wiring looms, so although all the same electrical boxes will be there, they may be in different locations.

The 4Auto doesn't work neither does 4High. 4Low partially works inasmuch as it changes down to the lower ratio, but the front wheels still don't have any 'drive'.

Thanks

Tony

 

[joecrna]

Joe is pointing you in the correct direction. I fear this will lead to the GEM. Expensive little begger but easily replaced by you. Getting a true diagnostics on the GEM, not so easy. Lets wait for Joe to lead you through some trouble shooting before we jump to conclusions.

 

[gijoecam]

Joe is pointing you in the correct direction. I fear this will lead to the GEM. Expensive little begger but easily replaced by you. Getting a true diagnostics on the GEM, not so easy. Lets wait for Joe to lead you through some trouble shooting before we jump to conclusions.

The fact that it's calling for 4wd properly, and properly changing between high and low range leads me to believe that the GEM and switch are working properly. I'm leaning towards either a wiring issue (broken brown wire between the TOD relay and the t-case), or a bad TOD relay itself.

Lets start with the simple stuff first:
Fuse junction box, #28(7.5A mini), #10(7.5A mini), #20(7.5A mini), double-check that the accessory delay relay is functioning (start the vehicle, turn it off, then without opening the door, verify that the windows still go up and down).

Check that out and let me know.

-Joe

 

[Maxcaddy]

Right, checked fuses 2, 20 and 28, and they are all 'intact'.

Started and stopped the engine and tried the windows, and they all went up and down until you open the door when they stop. (Didn't know they did that )

Jacked up the front and turned the front prop shaft by hand and one wheel turned, held that wheel and the other turned in the opposite direction.

Chocked the rear wheels (safely) and started it in 4High and put into 'drive' and the prop still turned freely by hand, so definitely a TC engagement problem.

I guess the radio comes out next ?

Cheers

Tony

 

[gijoecam]

Right, checked fuses 2, 20 and 28, and they are all 'intact'.

Started and stopped the engine and tried the windows, and they all went up and down until you open the door when they stop. (Didn't know they did that )

Jacked up the front and turned the front prop shaft by hand and one wheel turned, held that wheel and the other turned in the opposite direction.

Chocked the rear wheels (safely) and started it in 4High and put into 'drive' and the prop still turned freely by hand, so definitely a TC engagement problem.

I guess the radio comes out next ?

Cheers

Tony

Yup!

Here's what I would do... First, put the front end on jack stands and verify that, with the truck in park, you should be able to turn the front driveshaft by hand. (You'll see why in a minute...)

Pop the stereo out, remove the trim bezel from around the HVAC/stereo, remove the duct for the HVAC, and you'll see the TOD relay on the right side of the opening, above the glove box, just behind the dash panel, mounted to the brace.

I would unplug the connector on the relay, and attach a jumper wire with an alligator clip to the pin on the connector where the brown wire attaches to it. Then, you'll need a power source. If you don't have one laying around, I would recommend running to the parts store and picking up a cheap 12V cigarette lighter plug with a cord attached to it. They're about $5. Plug that into the auxiliary power point to provide power directly to the brown wire. If the t-case clutch coil is working properly, the front driveshaft will lock, and you will not be able to turn it by hand anymore. This simply verifies that the t-case is working properly.

Now, at this point, unfortunately I can't give you a conclusive answer as to whether it's a TOD relay issue, or a GEM issue. Without being able to monitor the GEM TOD duty cycle PID (output), I can't tell you for sure if the GEM is working properly or not. I would personally start with the TOD relay, probably getting a used one from a salvage yard or find someone on the board parting one out. The possibility remains that the TOD relay is fine, but the GEM output controlling it is bad... I just can't say without a proper diagnostic. Unfortunately, and educated guess is the best I can do for you at this point...

Give it a whirl and let us know what you find. Good luck!!

 

[Maxcaddy]

A quick look through the gap after taking the Radio out shows this on the right side

With the unit being this one

And on the left side is this unit

Can I assume the unit on the right which says 'sport utility automatic 4WD' (made in Canada) is the GEMS unit, and the TOD sits behind it ?

With my luck in finding the 'Brown wire', this could take me some time

I need to re-read the stripping of the surround from your BWM thread before going further. At the back of my mind is the idea that if the TOD or GEMS is dead then perhaps I could do a sort of BWM in reverse, whereby I ended up with the switch giving 2WD-4High-4Low ?

Thanks again for your continued support.

Tony

 

[gijoecam]

Pull the trim bezel off and let me see what else is around there... I take it we're not dealing with a US-spec Ex here, are we?

I suspect the one on the left with the sticker that says ARCM on it is the Automatic Ride Control module (do you have ARC?), and the one on the right appears to be the GEM... It may be behind the GEM, but I need to see more... the trim bezel is two screws above the HVAC controls, then pull the bezel off to release the spring clips, and then disconnect the 4wd switch, cigarette lighter, rear defrost, rear wiper, and fog lamp switches. Then, the duct has two screws at the very back of the opening (i see one in your first pic) and it'll slide out to gain plenty of clearance. Take a couple of pics of both sides of the opening and I'll see what I can figure out for you.

-Joe

 

[gijoecam]

Just glanced back at my picture... see the tab that sticks out from the bracket in front of the TOD relay? I suspect that's the bracket your GEM is hanging on... IIRC, there should be one screw that holds the GEM to the bracket... There are likely two connectors on the front of the module and one on either the top or maybe in your case, the bottom... Remove the front two connectors and you should be able to access the screw, remove that screw, and then you should be able to slide the module down off the tab and unplug the third connector.

Make sense?

I suspect that the TOD relay is right behind it in the same place as mine, but don't hold me to that...

 

[Maxcaddy]

.
.
.
Now come on, its never that simple with me


Behind the GEMS is ........

nothing which is because its the instrument console, as its a RHD export .

However, it does have the Automatic Ride Control and behind that box is this .....

and looking closely

is that the TOD with the famous brown wire in between the blue and the yellow ?

If so, I feel I'm now getting somewhere

Ciao

tony

 

[gijoecam]

Looks like it to me!!

That's the one you're looking for... They couldn't just build a mirror image of the IP now could they?!!?

Completely unrelated.... Is yours a column-shift or a floor-shift?