Ignition live

Simon6565

Registered User
Hi All,

I ripped out the abortion of towing electrics wiring last year from the boot of my 2008 Allroad, and it was installed by a “reputable“ company and replaced them with the westfalia kit.

My problem started when I couldn’t find an ignition / switched +ve in the boot. I kind of did but I’m not happy with it, so was wondering if anyone had any experience of finding an ignition on +ve.
Many thanks...
 

CupraDine

Registered User
To my knowledge there isn't one, the factory towing module uses the can bus to determine whether the ignition is on or not.

I have a relay in my wiring that switches when it sees 13.5 volts ish or more, if you search for towing relay you will find a similar one. I tried to find one when wiring in a rear dash cam and just used the relay instead.

The other option is to run a cable from the front, using a switched fuse from there and use that to trigger a relay in the back.

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Simon6565

Registered User
I was hoping not too to be honest but needs must I suppose. I bought a genuine Westfalia module and wiring direct from them and as I was installing 13 pin electrics I needed the option of the fridge power and battery charging so I bought the extra ‘kit’ , relay, wiring and hardly any instructions regarding where to source the ignition on power. They supply generic instructions so not much use as I don’t want to blow something expensive and render the car useless with a caravan and a livid missus in tow........
 

CupraDine

Registered User
My towbar was fitted by tow trust by a previous owner, and it has one of these charging relays fitted.
Charging Relay
A few seconds after starting the terminals marked 6 & 2 switch on and 12v supplied to whatever you need. The terminals are numbered for a Caravan 12s 7 pin socket which you can translate with a wiring diagram like this one.
 

Simon6565

Registered User
Westfalia are good enough to provide very detailed instructions and wiring diagrams with the 13 pin kit, you get a relay, a module and all the necessary wiring and plugs but where they fall flat is vehicle specific instructions for what they call their power plus extension kit. It basically gives you power connectivity on one of the pins that is left unconnected with an ordinary 13 pin system.
 
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