Does it matter? I prefer not to share the details of my personal life on the interwebs. But if it makes you feel better, I am in the USA.

 

Just to put this thread in context, all I plan on towing occasionally is a small utility trailer, here in Canada most small trailer lighting is the flat-4 plug.

White for ground, brown, yellow and green for position, turn signals and brakes.

On the back of the rear light "pods" on the vehicle are extra flat terminals for each of the lighting functions, I have traced the brake, turn signal and parking/position light circuits and plan on wiring to each corresponding plug with a heat shrink spade connector, run the wiring (inside split loom) down to the rear frame rails and install a water proof flat four receptacle directly into the bumper, all wiring will be dry and out of sight.....

Thanks for all the input.....

 

I was wondering if you were in Europe. If so I could understand wanting to use the Volvo one and I'm sure over there they might have trailers that plug into the 13 pin.

My problem with understanding your view is I can't pull up any of those part numbers nor can I get any pictures of them to maybe see and understand why you'd want to do it that way.

Anyway .....
"Also, what is this mysterious "5-wire" thingy you are talking about?"





It's not mysterious at all and other people get it quite easily. I explained how a number of car manufacturers have yellow turn signals in the rear. This adds an extra wire, thus the 5 wire thingy.
You have these wires on a yellow turn signal vehicle like a Volvo.

1. Ground
2. Tail or marker lights
3. stop signals (must be red by DOT regulations)
4. left turn signal, yellow
5. right turn signal, yellow

On most trailers there is no yellow turn signal lens. They share the brake light bulb with the turn signals. It's one bulb, one filament and in a car with red turn signals the turn signal flasher just flashes the brake light on the one side.

You need something electronic to connect wires 3,4 and 5 above and yet isolate them so you don't have both brake lights flashing at the same time. If you install the Volvo 13 pin you'd still need something to convert the turn signal pulse to work with the brake light bulb.

1. Ground
2. Tail or marker lights
3. Stop light and right turn signal
4. Stop light and left turn signal

This is the standard way a four wire trailer is wired. To be even more standard they even have it color coded and that is a standard that everyone follows too (or should).




It's dirt easy. You buy the converter that already has a flat four at one end and then attach the five wires at the other end to your cars tail light wiring.

I can understand you might not like splicing, cutting into or clamping a "scotchlock" onto the wiring but it's pretty simple and cost effective and it's unlikely you'll need more for the trailers most of us pull.

 

"You could also just make sure it's long enough to reach the trailer and leave it coiled up neatly inside the vehicle when not in use.
I do that on my wagon and my PU."

I can't stress this good advice enough.

I've towed boats, utility trailers, RV's and fifth wheels, and have found wiring the connector from the vehicle so it stays in the trunk (or out of the weather) when not in use will prevent 99% of the the problems with trailer lights. Intermittent grounds and shorted wires due to corrosion are usually the problem. This way when the lights on the trailer act up (and they will) you know that the problem is not with the wiring in the car.

If you are not going to use the Volvo wiring then solder and heat shrink (not vinyl tape) wiring splices. Corrosion is your enemy.

 

Trailer wiring for lights can be interesting. I found this Diagram that really helped me out a lot, hope it can do the same for you.