Tow Bar Wiring without special harness

[SweetAs]

Hi All,

Apologies if this is a avaliable in the search but it doesn't seem to work on my phone.

I've just fitted a witter tow bar but I didn't realise, as is with everything Volvo, they have their own special kits for wiring up the harness.

Am I good to just splice the wires in as usual with a DIY fit or do I really need this kit? At nearly £100 I would rather not. I'm also away camping as of Monday and we need the tow bar sorted.

If I'm good to splice in then does anyone have any diagrams or know of any good youtube vids to look at?

Any help is greatly appreciated :-)

[kenny]

Please do not splice into the wiring. You will cost yourself thousands of pounds in repairs. Do it right do it once. Take it on the chin and relax that it has been done right.

[SweetAs]

Hi Kenny,

Thanks for the reply.

Could you elaborate further please? Are there systems on the Volvo that I would be bypassing or tripping by not using their harness? I've done it a couple of times on other vehicles and its not been an issue so just wonder what's different.

I've just found a guy on youtube from etrailer.com who has spliced into the wiring and it wasnt an issue.

Like I said, not ignoring your advice, it just helps to have something to explain to the Mrs when I explain that we are shelling out another £100 that's all :-D

[SweetAs]

Found the video....

https://youtu.be/HUzzuKufLS8

[gmonag]

Don't use a universal wiring kit. Use the Volvo kit every time. They are about the same price, even cheaper sometimes and will just work.

[kenny]

Volvo spent millions designing you a great car with lots of Goodies like abs traction control. They went on to design a trailer module and wiring system that lets the car know when you have a trailer attached. When towing this system talks with the car and changes the way it brakes the way the traction control works when the gears change if you have an auto and alters throttle control etc. Your £100 gets you a lot more than just making the trailer lights work. Splicing wires stops all theses safety systems working and can overload lighting modules.

[Father Ted]

How old is your XC90?
Mine is 2003 and the official wiring loom is simply the wires with a plug on the end.
As mine was fitted with 7 pin and I needed 13, I cut the plug off and soldered to the tails. No problems.
I did the same on my 2003 V70 (same loom), again, no problems.

You will need to add two relays and two fuses. There is a diagram somewhere showing which to add.

The only issue doing it this way is that the fog light over-ride doesn't work, this needs to be programmed by a dealer. Basically, when your trailer is plugged in, it will turn off the car's rear fog lamp so you don't get reflected glare.

[jamessinclair]

hi does anybody know what kind of wiring system is in a volvo xc90 d5 2008

[gmonag]

If you are fitting a towbar, the best option for the wiring is undoudtedly genuine Volvo. It costs the same (even less) than unniversal wiring and is plug-and-play. Everything will work as it should - simples.

[S60D5-185]

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