TheKeymeister wrote: Tue Dec 15, 2020 10:46 am
Good morning ciclo,
I apologise, it seems we may have got our wires crossed (excuse the joke

) The instrument/cluster/switch lighting has always worked fine in the Transporter since doing the BCM swap. It has no dimmer next to the headlight switch, it only has a headlight level switch. The part number of this unit is 7H0 941 333. I think this probably explains why there is no wire in T73b/4, perhaps the instrument/cluster/switch lighting takes its feed along with the headlights on this low-spec model? Anyway, it works, so I am not too worried.
The issue I was having was with the interior lights (dome lights) not working on the 'doors open' setting, only on the 'permanently on' setting. I have restored the wire into T73a/4 now - and it has gone back to not working as before and producing an error code. I understand that, whilst it may have worked, T73a/1 is the incorrect position for that wire as it is to control other functions. I apologise profusely for suggesting your advice was incorrect

I wonder if it may be due to coding, or there is another position for this wire using this BCM
I understand your advice to swap the BCMs between Transporter and Caravelle, and have thought about this in great depth. With the Transporter, it's only me that uses it for work, I am not terribly upset by no interior lighting. The Caravelle I use with the family, including 4 children and a wife, no interior lighting would be a big problem. I really need to find a solution to this interior lighting problem before using this 089 BCM in the Caravelle - or at least be able to easily swap the 087 one back in if there is a problem. As such I think the best way forward for me on this occasion, would be to try and solve the interior lights in the Transporter with the 089 BCM, document the solution, and purchase a second 089 BCM for the Caravelle, and hopefully apply the same solution. If it doesn't work, I can easily re-install the 087 into the Caravelle until we find a solution. I hope that makes sense and you can see my logic

When I first attempted this upgrade on the Transporter there was very little info out there that I could find, only that 087/089/090 was required for cruise control.
I have also now borrowed from somebody at work 'another' VCDS cable, and it has allowed me to put the BCM coding to nearer the original, just with the bits changed for MFSW, cruise control, and one bit would not take the original coding as it said it was out of range. I can only apologise for my previous coding, I can now see how ridiculous it looks, I must have been drunk at the time as it was during the lockdown. I have also changed the byte on the engine ECU which has now allowed the cruise control to work. So the only outstanding problem is the interior (dome) lights now

Link to updated autoscan
here on pastebin
Thanks in advance for any advice regarding the interior lights...
My life would be meaningless without jokes, in fact I think my life is situated between the concepts of joke and nightmare

, crossed wires of all kinds have a tendency to find me.
I already imagined what your situations are with the two T5.1 and I was not wrong in my assumptions (it was not difficult to assume), which I understand and share in their entirety.
You don't need to apologize for anything, we do things, and if nothing burns, we can keep making mistakes until we find the solution. Nothing will burn with me here, you can be sure of it.
Just to inform you:
The power supply of the interior lights (dome lights) is carried out as follows.
- The BCM (any model) receives power through PIN T73a / 66, from the SB7, or SC17, or SC24 fuse (depending on the van model).
- and supplies this power by PIN T73a / 65 to power:
♦ Front and rear interior lights
♦ Luggage compartment lights -W18-, -W35-
♦ Illuminated entry strip -W31-, -W32-, -W33-, -W34-
♦ Glove compartment light -W6-
♦ Illuminated vanity mirror -W14-, -W20-
♦ Automatic anti-dazzle interior mirror -Y7-
If you want you can check the status of these fuses, although it really does not make sense because your dome lights work through the button.
I'm going to go over the BCM coding of the new autoscan, which makes the most sense from the first moment I've seen it.
I'll tell you something shortly.
Glad to hear that you already enjoy CCS in your T5.1 2011.
pettman wrote: Tue Dec 15, 2020 10:59 am
I think if you dont have the dimmer you need to get the part that has that in it and then install the wire
You need 7E0941333
It is an excellent solution.

Although it is possible to power the lights of the switches, A/C, instrument panel, etc. with pin T73b/4 (T73b/1) without having the Dimmer. I have never explained how to do it because all this adaptation is easier having the Dimmer, ... it is also included in the wiring diagrams (erWin, elsa).
Having the Dimmer makes it much easier to adapt all wiring when upgrading to a BCM Max, fewer wires are needed and it avoids cumbersome work because we use part of the original installation.
Without a doubt it is better to buy the Dimmer.