installing a tow bar

[cps13]

hi,

i am going to have a go a fitting a tow bar to an XC90. I understand that it has CANbus system so I have a bypass relay.

Has anyone fitted one of these relays, do you have any pointers?

Am I correct in thinking that you simply identify the wires in the cars loom for each light, splice into in and then connect to the bypass module, then connect to the trailer socket?

I was planning on stripping back part of the insulation on the existing car relay and soldering on the new wire. Would this cause issues?

Thanks,

[blaineuk]

And find a switched permanent live to power the relay.

[cps13]

blaineuk said:

And find a switched permanent live to power the relay.

Can I not simply connect to the battery? The battery is in the boot of an XC90 and provided it is wired correctly should not draw anything whilst the towbar is not connected?

cheers,

[blaineuk]

Yes you can do that.

[cps13]

blaineuk said:

Yes you can do that.

thanks

[shoehorn]

Be very careful,in fact Id trust it to someone who knows what they are doing.
A well known tow-bar fitting company sent a guy to my pals showroom to fit a tow bar to a Touran with a can bus bypass module and from what we could gather he ended up sending 12V down the 5V circuit,estimated repair parts costs were near £5000,the car was only worth that at best.

[cps13]

shoehorn said:

Be very careful,in fact Id trust it to someone who knows what they are doing.
A well known tow-bar fitting company sent a guy to my pals showroom to fit a tow bar to a Touran with a can bus bypass module and from what we could gather he ended up sending 12V down the 5V circuit,estimated repair parts costs were near £5000,the car was only worth that at best.

Honestly, I would question if he should have ever been sent in the first place if he was unable to determine the difference! Your comment, is also slightly contradictory, you called a well known tow bar company, so in theory someone who knows what they are doing, but they still Fu*cked it

Edited by cps13 on Wednesday 2nd October 23:00

[shoehorn]

cps13 said:

Honestly, I would question if he should have ever been sent in the first place if he was unable to determine the difference! Your comment, is also slightly contradictory, you called a well known tow bar company, so in theory someone who knows what they are doing, but they still Fu*cked it

Edited by cps13 on Wednesday 2nd October 23:00

That is my point exactly,
He fitted the module in accordance to the instructions as verified by myself,another guy(auto sparks) and whoever VW got to look at it but the module was not compatible with the car as verified by VW UK themselves,despite the manufacturer of the module claiming otherwise.
Its only a word of warning,from someone who has witnessed at first hand on a few occasions the results of connecting third party electronics to modern car wiring.

I`ve seen a Valeo park and beep parking sensor system fitted that only had a 12V+ from the battery,an earth supply and a trigger signal direct from the reverse light(as per instructions)cause a fault with the oil level warning in a 2008 S80 D5,showing an engine management fault in the cluster that refused to clear.
Someone had replaced the level sensor,the plug and the wiring up to where it joined the loom,all to no avail.
In between his booking and his appointment the owner,who figured it only happened since he had the park sensors fitted decided to unplug the park sensor unit himself.
He brought the car back in and the fault cleared and only returned after I plugged the park unit back in and activated it,once again it would not clear until the park unit was unplugged.
If I had not seen it my self then I would not have believed it but the proof is in the pudding as they say.