Trailer connection for Jayco 12 Pin plug

Thanks for putting up your wiring diagram John_Paul_128. I recently hired a van and towed it 4000 KM with my MY 2015 D4 with electrical connections on an adapter built from your post. Worked a treat. Perfect recognition of the trailer, green trailer light on the dash displayed with every indicator, reversing sensors turned off and car totally set up to tow the 2.5T monster on the back.

I did a lot of research before taking on the task and learned a few things that I thought were worth sharing. Hope you don't mind, but I have updated with my own wiring diagram, see attached. Welcome for anyone to make comment.

Things I can add are:

1. The 12N Pin 5 appears to come standard on the Disco as wired to the the RH tail lights. Unless you change this to an EBC output, the trailer brakes will lock on with a full 12V feed when your headlights come on. Could be really messy if you try and tow with the headlight switch on auto and you go through a tunnel or the sun drops behind a cloud or dusk comes around. Check Sneigy's post on the D3/4 Sticky zone on Electric Brake Controller Controller Installation - totally worth the 65 page slog to see some of the issues and get that one sorted out.

2. I love the flash buster circuit. Worked perfectly as stated above. Should work with either incandescent or LED trailer globes, so, if you are like me and you don't know what you are going to get when you hire a van, should work every time. Note the triple resistor arrangement = total resistance of about 6.3 Ohms = about the same as a standard 21W incandescent indicator globe. I got these from Jacar for almost nothing ('bout a dollar a pop). The three resistors combined are able to dissipate the heat well and I chose them after reading lots of stories about excessive heat coming of the Narva 21W single load resistor units. No issues on this circuit with heat.

3. The 12S plug - Only difference to the 12N plug is the male centre pin 7. I was running out of time to purchase a proper 12S plug off fleabay, so I just took a standard 12N plug and cut a longitudinal cut down the centre of the pin with a hacksaw, crimped the two halves toward each other (so the new pin fits inside the F pin 7 in the socket) with a pair of long nose pliers and hey presto -12N to 12S conversion - no waiting. Wrapped the outside of my creation in white electrical tape to identify which one plugs into which socket in the back of the Disco and all good.

Hope this helps anyone out there who is looking for a plug and play solution to wiring up without hacking apart their pride and joy (save for the ETBC, over to you Sneigy).

Attachment 135870