13 pin towing socket wiring
 

13 pin towing socket wiring

Here is a link to the socket wiring
https://caravanchronicles.com/guides...fault-finding/

and here is a link for a habitation relay but you will need to scroll down
https://www.campingandcaravanningclu...ectrics/page7/

link to TEC 3M relay wiring, again scroll down
https://www.ebay.co.uk/itm/Self-Swit...-/141896362193

I understand that if you have Al Ko ATC you need pin 9 permanent live but if you don't have ATC, why would you want pins 9 and 10 permanent live?
If the caravan is left connected to the car and not on mains hook up, for example on a ferry, by pins 9 and 10 being permanent live you can flatten the cars battery. Newer cars and caravans but I don't know what age should have relays to prevent this but our cars are not new and I am not convinced my caravan has a habitation relay

I have just checked one of my cars, pin 9 is permanent live, charging the leisure battery. If the fridge is set to 12v, not on electric hook up and engine not running, am I right in thinking the fridge will draw power from the leisure battery and in turn the car?


macafee2

As far as I know, the fridge cannot take power from either the on-board battery or from the car's battery. The only time the 12v feed to the fridge is operative is when the car's engine is running and the alternator is pumping out power.

Presumably you could connect a 12v bulb or similar to pin 9 and earth/chassis. If the item stays lit/on when the ignition key is out, you have a potential flat battery if anything is left connected to the tow socket.

I have just checked. I turned my fridge on and to battery, it started working.
I went to the garage and turned off the 240v supply to the caravans charger.
The fridge was still working on 12v meaning it must be getting its 12v from the leisure battery.
If pin 9 is permanent live as this is the pin that charges the leisure battery I will indeed get a flat battery on the car.

macafee2

I have a permanent live pin 9 on the tourer I bought from Rick. He suspected that the original owner who wired up the tow socket spliced it in with no relay to protect the car battery, and that many installations, especially on older cars, are set up that way for simplicity and speed of installation. Paradoxically, incorrect installation was a benefit to me when my battery went flat recently. I was locked out of the car and the manual key entry failed to open the driver's door so I couldn't pull the bonnet release. Fortunately I was able to recharge he battery via pin 9 and earth ( which couldn't have worked if there was the correct protection relay in place) and open the car with the fob. Otherwise it would have been a skinned knuckle job trying to get to the bonnet release cable via the wing. The downside is that anything connected to the tow socket will run down the car battery fairly quickly with the engine off, such as being on a ferry in transit somewhere, or a bit slow/distracted setting up at the pitch/campsite. Those were the days lol!

Are you saying pin 9 should not be permanent live?

macafee2

ok I am a bit wiser now
On newer caravans and I don't know when newer starts from but pin 9 "should" be permanent live. There should be a relay in the caravan that is powered by pin 10 which should be ignition live. When the engine runs this relay connects pin 9 to the leisure battery and disconnects the caravans 12v system, not road lights. The leisure battery is then being charged.

With the engine off pin 10 loses the live and the relay disconnects the car in 9 from the leisure battery and reconnects the caravans 12v system to the leisure battery.

Apart from the ATC I still don't think I can see the point of pin 9 being permanent live. I now need to see if my caravan has the relay I have referred to. Odd name, it is called a habitation relay. If not or it has failed that could be why the car battery went flat when the caravan was left connected overnight.

macafee2

So it may be that my tourer wiring is correct. I'm going to leave it 'as is', just because it saved me getting back into the car with a flat battery and a non- working key on manual.
Good luck sorting the habitation relay. Very useful info. I'll check if my pin 10 goes live when the ignition comes on later.

My tourer is wrong as I have pin 9 ignition live but my saloon which suffered the flat battery is permanent live, hence why the tourer is ignition live. I will leave the saloon as permanent live for now and hopefully in the next couple of weeks back the saloon onto the caravan and check what happens to the caravans 12v lights when the car is connected.

I do know the caravan radio seems to work when the car is connected as we have arrived at places to find the radio is on. I have not tried to replicate that when at home or on a site

macafee2