Any reason you didn't get one of the Westfalia or OE 13-pin kits? They come with full fitting instructions and are designed to connect in with minimum fuss (brown BCM plug aside!). They also integrate with the alarm, ESP, rear fog lights and (if fitted) reverse parking sensors.

 

In any case the wiring usually runs up the driver's side to the fuse panel there. What you'll need to do up there will depend heavily on the kit you have. At a minimum the bypass relay will need a power supply. If it came with scotchloks, you'll need to bin those and pick up a pair of harness adapters to plug into the rear light clusters or failing that get out your soldering iron to make the additional connections.

 

Your split-charging relay will need a separate high amperage power supply from the battery. If the relay doesn't come with suitable cable, you'll need to source this from an automotive wiring supplier. Anything else needed should be specified in the fitting instructions.

 

I've no idea if the car will need coding after this - I suspect not but someone who has done this type of installation should be able to say.

I would have gone with the dedicated wiring kit rather than splice into the wiring to avoid any potential problems with the Can Bus, it's sensitive enough already without making additions to it. If you're not confident I would take it to an auto electrician to ensure the job is done right.

As above you need a healthy supply from the battery.

 

Are you running a fridge and charging the leisure battery with it?

 

It works as you describe. Once the voltage is high enough (engine running and 12.7 volts or more) then the relay switches on and output power to the leisure battery and fridge. Once the voltage drops then it shuts off.

 

If you don't intend on charging your leisure battery or running your fridge then you can skip this relay.

 

 

On 12/04/2017 at 10:44, chimaera said:

Any reason you didn't get one of the Westfalia or OE 13-pin kits? They come with full fitting instructions and are designed to connect in with minimum fuss (brown BCM plug aside!). They also integrate with the alarm, ESP, rear fog lights and (if fitted) reverse parking sensors.

 

In any case the wiring usually runs up the driver's side to the fuse panel there. What you'll need to do up there will depend heavily on the kit you have. At a minimum the bypass relay will need a power supply. If it came with scotchloks, you'll need to bin those and pick up a pair of harness adapters to plug into the rear light clusters or failing that get out your soldering iron to make the additional connections.

 

Your split-charging relay will need a separate high amperage power supply from the battery. If the relay doesn't come with suitable cable, you'll need to source this from an automotive wiring supplier. Anything else needed should be specified in the fitting instructions.

 

I did get a dedicated wiring kit. Like I said I'm comfortable with most of the install, I was just wondering what colours were which in the loom. To save me having to get a multimeter and test every one. 

 

Also, do I really need that split charging relay? Won't the caravan run through the 13pin plug anyway? 

On 12/04/2017 at 11:40, CWARD said:

I would have gone with the dedicated wiring kit rather than splice into the wiring to avoid any potential problems with the Can Bus, it's sensitive enough already without making additions to it. If you're not confident I would take it to an auto electrician to ensure the job is done right.

 

I'm more than comfortable with the wiring and I've read enough posts about 7 way relays to know they don't effect the canbus. They're designed specifically to not effect it. 

 

Also, the extra £100+ For the dedicated wiring on top the total price of my towbar was not an option for me. 

On 12/04/2017 at 14:07, Phil-E said:

As above you need a healthy supply from the battery.

 

Are you running a fridge and charging the leisure battery with it?

 

It works as you describe. Once the voltage is high enough (engine running and 12.7 volts or more) then the relay switches on and output power to the leisure battery and fridge. Once the voltage drops then it shuts off.

 

If you don't intend on charging your leisure battery or running your fridge then you can skip this relay.

 

 

 

I do intend on towing a caravan so I do need auxiliary power for the fridge etc. I thought that the 13 pin plug would just feed that anyways? It used to on the old twin 7 pin plugs?

Just now, DIESELind said:

 

I did get a dedicated wiring kit. Like I said I'm comfortable with most of the install, I was just wondering what colours were which in the loom. To save me having to get a multimeter and test every one. 

 

Also, do I really need that split charging relay? Won't the caravan run through the 13pin plug anyway? 

When I say dedicated wiring kit, I'm talking about a vehicle specific kit that's plug and play for full functionality. What you described sounds like a generic bypass relay. It would help if you posted the details of the kit you have (supplier/part number/etc) so there's no further confusion.

 

If it's a 13-pin dedicated kit then everything should be ready to go from that. If it supports the full 13-pin functionality the instructions should direct you to fit fuses 8, 9, 43, 44 and 45. 43 and 45 are the ones for the switched and permanent +12 V to the caravan.

Sorry it was a typo. 

 

It it was meant to read "I did get a 13 pin pre wired universal kit" not a dedicated kit.

 

The latter of my original question still stands though. 

 

Any ideas?

 

Also if I do fit it but don't necessarily need it, how much of a benefit is it? 

This is the pinout and wire colour for the euro 13-pin connector: http://www.uk-trailer-parts.co.uk/wiring-a-13-pin-euro-plug/

 

The idea of the relay is that it only switches on power to the trailer via pin 10 when the battery voltage on the car is sufficiently high and the ignition is switched on. Without it, your caravan is drawing power as long as it's connected which could be a problem if you're parked for an hour or two for a break with the engine off.

 

The OE kit I installed on my Superb (I'd expect Octavia to be similar) goes a step beyond this in that the controller can be configured so that pins 9 and 10 are only powered when a trailer is plugged in.

 

As for how best to hook all of this up to your car, I'll leave that for someone who has done the job this way. This diagram shows the basics for the relay:
 

Ok. That's great. I'll just fit it I have to run the cable for one so I may as well don't for the other. 

 

So there's no list of what colour the cables are on the vehicle loom rather than me get the multimeter out?

 

My next and last (I hope) question on this is...

 

Should I run the power direct from the battery? Or can I just use an "add a fuse" via the fusebox?

Edited 13 April, 20179 yr by DIESELind
Missed out information

I'm pretty sure you still need it. It will supply the 12v to the 13 pin socket.

Thanks for all your input.

 

I used the piggy back fuses in the fusebox for 12V feeds and used a multimeter to find the colours. Although I did find (and lose soon after) a thread on Briskoda showing them. 

 

 

It took me approx 10 hours over two days. I would have been done much sooner today if I hadn't have forgotten the earth coming from the 13pin socket.