Hi I have a 2018 Motorhome based on a chassis cab with an ALKO chassis.
I wish to fit a Towbar, but am struggling a bit with the wiring for the rear lights.
Anyone know what the colour codes should be?
Also I need to find the wiring loom so I can fit the Canbus relay,( in the battery box) ideally I’d like to locate the FIAT factory wiring at the chassis cab where the MoHo converter has connected his loom. Anyone know where this could be?
I presume there was some kind of plug/socket arrangement left for the converter to connect up to, I also suspect this will be somewhere on the nearside of the vehicle, but where?

Hi
Just updated a post (Below) from 2017 that probably has the info you require regarding the rear lights & location of the Outfitters connections & wiring plus colour codes etc
https://www.fiatforum.com/ducato/448361-ducato-x250-rear-speaker-wiring.html?p=4476701
Hope that helps
Cheers

Free spirit
That looks like the best info I have seen. So I presume with my MoHo being supplied as a Chassis cab that the rear lighting plug socket is item 8 Y203 L4A (12 way) and this is located at the OS B post? Just need to identify the colours to the lights to allow me to tap in for the Can bus relay

L19 JGB said:

Free spirit
That looks like the best info I have seen. So I presume with my MoHo being supplied as a Chassis cab that the rear lighting plug socket is item 8 Y203 L4A (12 way) and this is located at the OS B post? Just need to identify the colours to the lights to allow me to tap in for the Can bus relay

Click to expand...

Bugger thought I had this!
I have a Swift wiring diagram which starts from “FIAT Rear Light Connector Y203”, which tallies with the info from FreeSpirit, so was expecting to find this connector plug at the base of the B Post. Yes there are 2 plugs there, see fotos. I thought the larger plug (15 way) would be the one, but the colour coding was not correct. When I unplugged this, the side marker lights went out, but I still had tail lights. I tried the six pin plug but again the tail lights were still on.
Removed the cover on the passenger side B Post, but all there is in the is the diesel & Ad Blue filling pipework!

I fitted my towbar and electrics using appropriate language and a great deal of patience.
I found the wiring under the right side step and using a circuit tester found the correct wires. I could not find any colour pattern in the Fiat wiring harness that would be helpful.
I had to fit a multiplex bypass relay which I think would be required for almost any these vehicles but once you get it sorted, it should be good to go.
I bet that was helpful !!!!!!!
Good luck.

..you may find pages 96-100 in the X290 upfitters manual (recently uploaded to the Downloads section here, under Ducato) may give some more useful information on this. It certainly has the wiring colours at the rear connection, and may help with the location of various connectors at the front.

https://www.fiatforum.com/downloads.php?do=download&downloadid=550