CDL Electrics on Disco II for Diff-Lock Lamp

[jmkoffice]

Hi all, the vehicle refered to below is a 07/02 Discovery II TD5 Auto

I have converted my non-CDL LT230SE transfer case to incorporate a 2004 DII CDL. A 2004 DII CDL shift has been fitted to the vehicle to enable the CDL to be activated from the cabin. This arrangement is now what a late model 03 - 04 DII has from factory.

The job is almost done. The 04 TCase housing fitted has two switches, one is definitely a "diff lock" switch and the other is somewhat mysterious. Research has indicated it could be a temp sensor, neutral sessor or both switches are used in parallel on the 2004 to activate the diff lock lamp on the dash. THis also depends on which country the TCase comes from.

The switch/s are not a simple on/off type. Depending on the switch position either a voltage of 1.8v or 7.7v is supplied to earth for the diff lock lamp via the Instrument Pack.

This switching is a problem for DII discos without the appropriate wiring in the loom supplied to the gbox and TCase. Has anyone worked out how to utilise these switch/s on the TCase on non CDL wired models?

Thanks in advance

Johann

[Slunnie]

It's not the low/high range switch so the ECU knows which throttle map to use is it?

[WildOne]

Hi/Low selector switch is on the top of the Front output housing, beside the Hi'Low selector lever, orientated horizontally and pointing toward the front of the vehicle.
The CDL switch is about half way down the Front output housing orientated vertically.
Even though my D2 came from the factory without any cdl internals at all, i found that the wiring loom still had all the connections required, complete with plugs.

[Graeme]

The 03/04 TCs have 2 switches for the diff lock, wired in parallel. This causes the CDL light to be lit if the CDL is trying to lock or is locked. You will just need to add wires to parallel-up the 2 switches if you want to use them both.

I assume the voltages you are quoting are those from the workshop manual. The switches are definitely simple on/off type, its just that the instrument electronics consider voltages below the low voltage to be open-circuit and the higher voltage to be closed circuit.

Edit: In this instance, low voltage = at least 1 switch is closed, high voltage = neither switch is closed.

[jmkoffice]

Hi/Low selector switch is on the top of the Front output housing, beside the Hi'Low selector lever, orientated horizontally and pointing toward the front of the vehicle.
The CDL switch is about half way down the Front output housing orientated vertically.
Even though my D2 came from the factory without any cdl internals at all, i found that the wiring loom still had all the connections required, complete with plugs.
The only free plugs in the loom routed next to the TCase illuminates the "Transmission High Temperature Warning Lamp" on the right side of the instrument cluster.

Could the required diff-lock wires and plugs be hidden in the loom from factory? It would be good to be able to use the correct wires so the TControl can be controlled when the CDL is engaged depending on engine state.

FYI: The switches show a closed circuit continuously when resistance is tested. Electronically, a low and high voltage can be considered on or off. If I cannot find the factory diff lock wires, rigging up a seperate warning light is not going to be easy.

[ozscott]

I am watching this thread with real interest because I am keen to do a CDL (either with a D1 output housing or later case entirely) in my late 01 build series 2 V8....the question of whether the wires were there ready to activate the CDL lamp is a question that I have asked many people and so far noone knows for sure....if its not there I doubt I would bother with the conversion.

Cheers

[jwb]

I had a conversion done on my 2002 D2 and the difflock warning lamp wires were there.

[jmkoffice]

JWB, can you supply more details please....

Is it an electric CDL actuator you had installed as opposed to the factory shifter?
Are you using the original diff-lock switch/s located on the top op the LT230SE TC?
With regard to the wires, did you find the wires yourself or did a Auto Electrician do it for you?
Were these wires hidden in the loom or located in a loom inside the centre console?

Cheers

[Graeme]

The only free plugs in the loom routed next to the TCase illuminates the "Transmission High Temperature Warning Lamp" on the right side of the instrument cluster.

Could the required diff-lock wires and plugs be hidden in the loom from factory? It would be good to be able to use the correct wires so the TControl can be controlled when the CDL is engaged depending on engine state.

FYI: The switches show a closed circuit continuously when resistance is tested. Electronically, a low and high voltage can be considered on or off. If I cannot find the factory diff lock wires, rigging up a seperate warning light is not going to be easy.
The wires for the transmission temp light are on the LHS of the TC and there is a plug high up on that side that can be replaced with the temp switch that's used in V8s.
Maybe the wires for the diff lock, if they exist, are still above the gobx somewhere nearer the RHS.
If not then I'd expect the wiring loom inside the vehicle that runs under the centre console would be complete and just the extension wires from there have been omitted. You could remove the console and check for the presence of the correct colour wires.

[jwb]

I had an 03 front output housing and factory actuator installed on my existing transfer case so internally it all looks like an D2a set up. The guy who did it found the indicator lamp wires in a loom above the case and connected to the switch on the housing. I haven't actually looked under neath but it all works don't know if the connectors were there or the loom that came with output housing was simply spliced in.

[ozscott]

just want to resurrect this thread...how did the wire hunt go matey? I am interested and I think others would be too.

Cheers

[jmkoffice]

just want to resurrect this thread...how did the wire hunt go matey? I am interested and I think others would be too.

Cheers
Unfortunately, progress is slow. I need to confirm connectors C761 & C552 are present under the centre console as shown in the diagram. If so, it may be a case of installing a 99 - 01 wiring harness. C552 is an earth connector which will require an older model harness as well.

Otherwise a D1 switch can be installed in the TCase and a seperate LED installed in the decal for the CDL console lever.

Maybe someone will have time to confirm this before me.......

[jmkoffice]

Well, some good news for my fellow CDL Installers - The part number I used for the transmission/Transfer Case wiring harness isYMD111880 - from a June 2001 model.

When this wiring harness is compared with my 2002 harness, there is only 1 extra pin used. This confirms what I found out from Rave earlier in this thread. It takes about an hour to comfortably R & R the new harness.

The only thing left to do now is to transfer the CDL decal from a D1 console to my D2 console. The dimensions are the same, so hopefully a heat gun used gently will remove my D1 decal so I can glue it over my D2 one.

My CDL install job is now almost a 100% LR factory installed CDL.