L90 BCM

L90 BCM

Active Member
Hi all I am in the process of stripping down my wiring loom and wondered if someone knows what this bit is for?
I have searched and I think it is where you can plug in a relay to prevent a caravan from draning you car battery when the engine is of. If so does any one know where I can buy it from? Thanks Ben

I think it normally sits in the back corner , not sure as it's out of the vehicle now lol


 
I have found where it sits, while looking through p38's d2 build ha ha
This is his picture
5EB3DF49-9121-4E48-92FC-9D4D91A3BB7F-4473-0000096DBD387F02.jpg
 
It is connector C0905 which is involved in the rear fog light circuit to the trailer socket, looks like it just links two bits of loom together, probably the LH and RH vehicle fog lights and the towbar socket feed:

Disco2C0905Connector.jpg


Disco2C0905Connector2.jpg


Your relay should be part of the main fusebox under the bonnet, details of fitting the relay are given in the towing electrics fitting details in RAVE.

Peter
 
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Cannot thank you enough :) just what I was after, at least I know that it needs be be there and stay connected :) for what I want to do.

I don't suppose you would know which wires would need bridging to fool the alarm system that a door is locked/shut ?
I am basically making a 5door disco into a 2 door defender, and I want to keep the alarm :)
 
Not without trawling through the schematics, which I haven't got time for right now.

Peter
 
The alarm is a bit involved to say the least, but the driver's door switch lead is Purple/White going into the BCU at C0660-17, and the four others doors combine into a Purple/Light Grey going into the BCU at C0660-4.

Peter
 
Yes that would make since as one press of the unlock just does the drivers door and then a second press releases the other four ;)

Where are you finding all this great knowledge, I attempt to look at the wiring diagrams on the web but it's a bit confusing lol, and I am studying bloody electrical electronic engineering. Ha ha god help me :)
 
Another quick question.
Do you know what the green with a orange trace wire is that I believe to be the earth for the rear light, but I am not sure as it's not black lol ?
 
L90 BCM said:
Where are you finding all this great knowledge, I attempt to look at the wiring diagrams on the web but it's a bit confusing lol, and I am studying bloody electrical electronic engineering. Ha ha god help me :)
Click to expand...

The schematics that you've seen on this thread are from the RAVE CD (disc 2 iirc for disco 2 and freelander).

There are links to the RAVE downloads in numerous places on the forum.
 
L90 BCM said:
Another quick question.
Do you know what the green with a orange trace wire is that I believe to be the earth for the rear light, but I am not sure as it's not black lol ?
Click to expand...

All grounds are black, so it is probably something not lights-related.

Green with orange tracer comes off the passenger fusebox and goes to the brake pedal switch, then with a reversed orange with green tracer to the engine ECU etc.

Green with RED tracer is the LH indicators.

The same colour scheme can be used for different areas, where is this wire located?

Peter
 
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listerdiesel said:
All grounds are black, so it is probably something not lights-related.

Green with orange tracer comes off the passenger fusebox and goes to the brake pedal switch, then with a reversed orange with green tracer to the engine ECU etc.

Green with RED tracer is the LH indicators.

The same colour scheme can be used for different areas, where is this wire located?

Peter
Click to expand...

It is located in the headlining loom it comes from, as I can see the bottom passenger corner brown connector, the one with the heater rear window winning in it lol and then I goes all the way to the rear light I think. Might be wrong as the loom is out the car and on the lounge floor ;)
 
L90 BCM said:
Hi all I am in the process of stripping down my wiring loom and wondered if someone knows what this bit is for?
I have searched and I think it is where you can plug in a relay to prevent a caravan from draning you car battery when the engine is of. If so does any one know where I can buy it from? Thanks Ben

I think it normally sits in the back corner , not sure as it's out of the vehicle now lol


Click to expand...



That connector is a 'jumper' to complete the rear fog lamp circuit to the towing electrics pickup connector.

There's an optional relay that plugs-in at that connector (the 'jumper' is removed and disgarded), which cuts-out the vehicle's rear fog lamps when a trailer is connected to the towing socket.

The kit is part number - STC50181

STC50181-01.jpg




STC50181-03.jpg




It uses an unusual 3-terminal relay, which has its coil in series with the trailer connector's rear fog lamp(s) circuit, so that, with a trailer connected and the rear fog lights turned-on, the coil is energised and the relay's contact opens, thus disconnecting the vehicle's rear fog lamps.

The trailer's fog lamp(s) are then powered through the relay's coil.

I have a drawing of the circuit somewhere, I'll post it, when I find it.

.
 
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L90 BCM said:
It is located in the headlining loom it comes from, as I can see the bottom passenger corner brown connector, the one with the heater rear window winning in it lol and then I goes all the way to the rear light I think. Might be wrong as the loom is out the car and on the lounge floor ;)
Click to expand...



That will be the Light Green/Orange trace wire, which goes from C0485/C0480 in the LH footwell, to the radio aerial amplifier, mounted up in the RH side of the roof.

.
 
L90 BCM said:
Cannot thank you enough :) just what I was after, at least I know that it needs be be there and stay connected :) for what I want to do.

I don't suppose you would know which wires would need bridging to fool the alarm system that a door is locked/shut ?
I am basically making a 5door disco into a 2 door defender, and I want to keep the alarm :)
Click to expand...


The micro-switches in the door locks, switch the signal wire from the BCU to earth when a door is opened.

As Peter has said, the driver's door is on a separate circuit to the other doors, which are all in parallel, on the same circuit.

So, you can just leave the rear side and tail door harnesses disconnected and then, as far as the BCU knows, all the doors are present and closed.

As, there's no separate door harness for the tail door (its wiring is at the tail-end of the roof/body harness), you might want to strip-out the Purple/Light Green trace wire, which runs from the Light Grey connector junction in the LH footwell (C0102/C0484), all the way to the 8-way MQS door motor connector (C0831).

.
 
PaulMc said:
The micro-switches in the door locks, switch the signal wire from the BCU to earth when a door is opened.

As Peter has said, the driver's door is on a separate circuit to the other doors, which are all in parallel, on the same circuit.

So, you can just leave the rear side and tail door harnesses disconnected and then, as far as the BCU knows, all the doors are present and closed.

As, there's no separate door harness for the tail door (its wiring is at the tail-end of the roof/body harness), you might want to strip-out the Purple/Light Green trace wire, which runs from the Light Grey connector junction in the LH footwell (C0102/C0484), all the way to the 8-way MQS door motor connector (C0831).

.
Click to expand...

Does this mean I could just remove the connected and wires for all the doors bar the drivers and then wire the passenger door in parallel with the drivers door so it will unlock on one press of the fob and not two like normal :)
 
L90 BCM said:
Does this mean I could just remove the connected and wires for all the doors bar the drivers and then wire the passenger door in parallel with the drivers door so it will unlock on one press of the fob and not two like normal :)
Click to expand...

Possibly.

The double unlock is programmable in the BCU.

Peter
 
L90 BCM said:
Does this mean I could just remove the connected and wires for all the doors bar the drivers and then wire the passenger door in parallel with the drivers door so it will unlock on one press of the fob and not two like normal :)
Click to expand...


No, don't connect the driver's and passenger doors together, they're wired to different terminals on the BCU, and perform different functions.

The 'driver's door open' function, does things like sound the 'lights on' warning, when the driver's door is opened (and the lights are on).

The 'other doors open' functions are separate to this.

'Single point entry' - which unlocks just the driver's door on the first press of the remote, can be turned-off in the BCU (using Nanocom, Hawkeye, etc...), so that all the doors unlock on the first press of the remote.

.
 
Ohh that's good to know I can turn it off, so if I just use the original front pass and driver door connecters and discard the rest it should be ok :)

Don't think I will need that green with orange trace wire either as I will be using a rubber #### type aerial like a defender ( he says ) :D

I have other issues with the fuel sender wires aswell :confused:
 
L90 BCM said:
Ohh that's good to know I can turn it off, so if I just use the original front pass and driver door connecters and discard the rest it should be ok :)
Click to expand...


Yes, that will work
icon_thumbup.gif




L90 BCM said:
Don't think I will need that green with orange trace wire either as I will be using a rubber #### type aerial like a defender ( he says ) :D
Click to expand...


That Light Green/Orange wire is powered via the 'auxiliary circuits relay' on 1.5mm² cable, through the same 15A fuse as the head unit's ignition-switched supply (F16 in the interior fuse box), so could be useful for something.



L90 BCM said:
I have other issues with the fuel sender wires aswell :confused:
Click to expand...


What issues ?

.
 
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