Volvo European 7-pin to US 7-pin

[EllPea in CA]

Just in case anyone else has this issue... My Volvo mechanic has been a little flummoxed in deciding how we should deal with this. His solution was to order a European 7-pin for the trailer and wire it in, but he was somewhat uncertain about what changes this would make.

I spoke to the local trailer supply and repair people, and they were unable to confirm if they could help me with this or not without looking at both trailer and car connections. Those aren't available for viewing until hitch is installed in 7 days.

And there was a hitch guy from U-Haul standing behind me, and he chimed in that they won't even do Volvos at his shop for just that reason. Sheesh.

Plus we *do* want to be ready to tow and actually leave town at some point.

I just called and spoke to Customer Service at e-trailer, and they were able to resolve the issue in about 30 seconds -- they have a "7-way to 7-way" adapter made for just this purpose. No hard-wiring, just plug and play.

Wow. Pretty simple! Only 24.95 plus shipping.
Happy camper.

Cheers,
Ellpea

[Andrew Gibbens]

If anyone can sell you a European 7-pin to American 7-pin connector, be sure to stock up on snake oil at the same time. They aren't just different shapes, they have different conductors too - for example, no European trailer has electric brakes, so there's no brake conductor in a European 7-pin. Plug-and-play will be more like plug-and-don't-play.

[EllPea in CA]

Originally Posted by Andrew Gibbens

If anyone can sell you a European 7-pin to American 7-pin connector, be sure to stock up on snake oil at the same time. They aren't just different shapes, they have different conductors too - for example, no European trailer has electric brakes, so there's no brake conductor in a European 7-pin. Plug-and-play will be more like plug-and-don't-play.

Ah. well. Thanks for raising my previously-relieved anxiety level back to red-alert.

Do *you* happen to have a solution to offer?

[tractors1]

Good info here: UKAirstreamers.org - View topic - American trailers and brakes - Government fact sheet

Airstream does biz in Europe.

[EllPea in CA]

Originally Posted by tractors1

Good info here: UKAirstreamers.org - View topic - American trailers and brakes - Government fact sheet

Airstream does biz in Europe.

Thanks Charlie. This was informative. I didn't find an answer to my specific question, but the last post mentioned:

"Four wires coming out of back of brake controller are :

Black - Battery positive

Red - Cold side of stoplight switch

White - Ground

Blue - To brake magnets via 7 pin umbilical cord."

I do recall Volvo specialist telling me that their 7 pin only used 6 wires, the 7th was available for "whatever" we wanted, and he did mention wiring the brakes through that pin.

So perhaps this is not as complicated?

[tractors1]

The trailer side US connector also has an uncommitted 7th pin; often used for back up lights on some trailers, or the ignition switched side for controlling the LP/12V switchover of the fridge (Escape doesn't use this feature on theirs.)

[EllPea in CA]

Originally Posted by tractors1

The trailer side US connector also has an uncommitted 7th pin; often used for back up lights on some trailers, or the ignition switched side for controlling the LP/12V switchover of the fridge (Escape doesn't use this feature on theirs.)

So is making this adaptation as complicated as everyone is making it sound?

[tractors1]

Originally Posted by Ellpea in CA

So is making this adaptation as complicated as everyone is making it sound?

Probably not, but without the pinout configuration of the Volvo side I can't be certain. Shouldn't be a big deal as the trailer side connector can be configured to match up the functions. Any RV/trailer type store that sets up 7 pin connectors could do it.

[EllPea in CA]

Originally Posted by tractors1

Probably not, but without the pinout configuration of the Volvo side I can't be certain. Shouldn't be a big deal as the trailer side connector can be configured to match up the functions. Any RV/trailer type store that sets up 7 pin connectors could do it.

So, I have these options... which would you say is most likely the solution?

1. Try to re-wire existing US trailer connector to match European auto-side plug.

2. Wire in European trailer-side connector to trailer.

3. Leave all as is and use 7-way to 7-way adapter, which e-trailer says will solve difficulty.

???
Thanks for your assistance on this quandry!

[tractors1]

I would definitely buy the adapter as it probably makes the geometry work on the rubber shapes so things would fit together. Can always send it back if not needed.

If it solves the problem, you're done! If not:

Trailer side is easier to rewire to match the Volvo side and seal to weather. Down this page you will find the US standard pinout functions, so you might need to change the trailer side connector (rewire) and match the Volvo pin functions:

Trailer Wiring Diagrams | etrailer.com

[Byron Kinnaman]

The last thing I would do is to rewire the trailer side. At some point in time you're going to want the trailer pulled with some other vehicle, creating an incompatibility is pretty risky business.

[Bob Miller]

Yep, I agree, the trailer, the TV and You are all in North America, I would wire them to match NA standards. Putting a standard NA 7 pin connector on the Volvo isn't going to be that big a deal and you will have the brake line available should you need that as well. Our Lil Bigfoot had electric brakes, does yours? While not required by CA law (<1500 lbs) they are nice to have if ya got em'

[Andrew Gibbens]

Originally Posted by Bob Miller

Yep, I agree, the trailer, the TV and You are all in North America, I would wire them to match NA standards.

That makes good sense and a competent hitch installer should be able to achieve that - adapting the Volvo wiring as necessary.

E-trailer do indeed list a 7-pin converter - but it appears to connect a US 7-pin round-pin plug to a US 7-pin flat-blade socket, so neither end is Euro 7-pin, which is why I suggested it is unlikely to help. It sounds like e-Trailer may not know about Euro plugs.

[redbarron55]

Usually the brake / turn lights are separate on the Euro hookups. You will need a three wire to two wire converter. I rewired my VW 13 pin (which is the basic 7 pin plus 6) to 7 pin North american standard.
something like this:

https://www.etrailer.com/Wiring/Curt/56200.html

Most are powered from the car to keep from loading the car's lights and some of them have light out detectors etc and the circuits can be confused if they are not isolated.

I would suggest just installing a new connector to replace the euro connectors Hopkins makes one that has both the 4 pin and 7 pin with covers. In the US you will most very likely never see a 7 pin euro trailer (13 pin either).
The euro trailers have separate lighting circuits for running, brake, turn, fog, and reverse so that the car can test for bulbs burned out as is required by law.









Just pick pick out the left and right turn wires, brake light, and one of the tail light wires and hook them up to the converter and from the converter the the proper pins on the 7 pin US connector and then the brake wires and power from the car.
I used a non-powered converter since I needed to have power drain to turn on the trailer detect circuit on the VW.

[Bob Miller]

The converter that Redbarron55 mentioned is a standard autosupply/trailer shop item Whoever does the installation should have those on the shelf. I kept the one out of our CRV when we took the hitch off. It was plug & play with the Honda harness. Did you check to se if Volvo has a similar part?

[EllPea in CA]

Originally Posted by Bob Miller

The converter that Redbarron55 mentioned is a standard autosupply/trailer shop item Whoever does the installation should have those on the shelf. I kept the one out of our CRV when we took the hitch off. It was plug & play with the Honda harness. Did you check to se if Volvo has a similar part?

I've pretty much trusted my Volvo guy to handle the Volvo end of this. He's done the install for many local vehicles, and has done one on his own -- for him the Volvo/European connection works fine with a converter to his 4-pin. The part he's uncertain about is the best way to make this work with my trailer.

LP

[tractors1]

Originally Posted by Ellpea in CA

I've pretty much trusted my Volvo guy to handle the Volvo end of this. He's done the install for many local vehicles, and has done one on his own -- for him the Volvo/European connection works fine with a converter to his 4-pin. The part he's uncertain about is the best way to make this work with my trailer.

LP

Thats' because the standard 4-pin (aka UHaul) connector does NOT include a 12V charge line for your trailer battery or a brake signal line. I think you need to go to an RV or trailer shop for guidance at this point.

[EllPea in CA]

The trailer service is next on our list. He's doing our trailer hitch because it's his ballywick, and the local people (like U-haul) won't do a Volvo. We'll take it in with a selection of 7-pin connectors and adapters -- they can choose what they know how to do and what works for them.

I just mentioned 4-pin because that's what Volvo guy uses for his tent trailer. He/we know we need the 7 pin to charge battery and operate brakes.

Thanks for the great wiring charts and details. I hope I don't have to pull any of this up for the trailer service people... although if they don't already have a handle on it maybe I should tow it somewhere else!

[Bob Miller]

Easy Peasy answer.... There are 7 pin connectors for the TV that come pre-wired with a flat 4 connector pigtail for the lights. Put the flat-4 line with it's light converter on the Volvo and plug it into the pigtail on the 7 pin and you are good to go. Just add the charging line and brakes. Looks like this one from etrailer:
Adapter 4 Pole to 7 Pole Vehicle End Trailer Connector Tow Ready Wiring 30717

[EllPea in CA]

Originally Posted by Bob Miller

Easy Peasy answer.... There are 7 pin connectors for the TV that come pre-wired with a flat 4 connector pigtail for the lights. Put the flat-4 line with it's light converter on the Volvo and plug it into the pigtail on the 7 pin and you are good to go. Just add the charging line and brakes. Looks like this one from etrailer:
Adapter 4 Pole to 7 Pole Vehicle End Trailer Connector Tow Ready Wiring 30717

Sounds great, BUT -- the 4 pin doesn't enter into this scenario! It did for Volvo Steve, because that's what *he* has going.

I think we used the 7pin to 4pin adapter when we towed home with the Aerostar (it only has a 4 pin).

But in the current scenario the need is to connect auto's European 7-pin to trailer's US 7-pin and have it actually work. So complicated.

My eyes are actually beginning to spiral a bit, like Lucy in the Sky...!