First of all, hello all! I've been loitering for 12months or so since buying a FL2, but as is often the case, a technical issue has pushed me to register such that I can pick your brains.

I have a towing electrics issue that myself, the towbar fitter, local caravan dealer and the kit manufacturer are all baffled by, I wonder if anyone has experienced similar. I am in the off-highway automotive industry and have worked with auto-electrics and Canbus for years but this one has me stumped.

When I purchased the FL2 it had twin 7-pin electrics, which when connected to my 2015 Swift via a 7 to 13pin adapter turned the van into a disco! All the exterior lights would flash randomly for varying periods of time between 30s and, well, sometimes it just wouldn't stop and the "smart" relay in the boot was clicking away at full chat.

I decided to get a dedicated 13-pin kit fitted and coded which has now been done and all is fine, except for one thing. The caravan reverse lights don't work....

BUT, get this...

1. The fitter tested the reverse lights on his test box and a new trailer and they worked fine.
2. The caravan delaer has tested the van on their test box and two other cars, all works fine.
3. I even put 12v across pins 8+3 on the van and, sure enough, the reverse lights work fine.

So, both the FL2 and the van are working correctly in their own rights, just not when connected together. All other functionality of the towing electrics is spot on, lights, fridge, perm & switched live etc. Whern I returned to the towbar fitter, the reverse lights didn't work on their test board initially, but after switching side lights on they came back to life. They changed the can module and re-located the earth just to be safe, but symptoms remain exactly the same, it's like something trips out when I connect my car and van, but is able to reset and work OK with other light boards.

Anyone ever experienced something similar?

Are they LED lights on the caravan?

I understand from the caravan forums that LED lights can cause strange problems.

That was the first thing the fitter asked me, but, nope, all filament bulbs.

Do the car reversing lights come on when in reverse with the caravan connected?

Yes. Also the parking sensors are silenced when connected to the van so it would appear that the correct canbus signal is present and being identified.

Having said that, I think the PDC is disabled by the body control module which identifies the van as being connected by an earth return???