Fridge issue.

Can you supply more information?

Is this a new to you car and/or caravan?    Or a set up that used to work?

Do you have the caravan handbook?   And the technical handbook which has the wiring diagrams?

Even if you are doing something wrong, it should NOT be possible to connect the fridge element directly to the caravan battery.  Are you sure it is the fridge that is draining the leisure battery?      

We have a Swift Group van, but an older model (2008), we have the control panel above the door on, but there is no need for us to select caravan battery or car battery.  When towing we select battery operation on the fridge, it has a little blue light and this flashes until the car is started up, then shines steady.

 I would expect that  newer cars will have to be programmed to supply power via the 13 pin socket, certainly our 2016 VW did.  Pin 10 supplies the fridge and the  habitation relay, pin 9 is the permanent live.

It sounds like you  could have a wiring fault or a faulty relay.

Even if you are doing something wrong, it should NOT be possible to connect the fridge element directly to the caravan battery. Are you sure it is the fridge that is draining the leisure battery?

I agree and you need to be looking elsewhere for the problem. I would first start by ensuring your leisure battery is ok. How old is it, is it in good condition?

peedee

A little more of our experience in case it might be helpful, or of interest, though probably not relevant for the OP............

We had no problem with the combination of a 2007  Volvo and our previous 1998 Swift or present 2008 Swift, but with the VW it was a different matter, cars are so much more complicated and technical these days!

It has what I believe is called a smart alternator, this meant  it only maintained a certain charge to its own battery and did not really do much in the way of charging the caravan battery.  We also were not convinced that it was doing much for the fridge, but as it is well insulated it did not matter so much.

The van battery was a different matter as we sometimes ran out of power for operating the mover on arrival, an essential piece of equipment on a twin axle van.    According to what I read somewhere, it also seemed possible that the car battery might even be pulling power from the van battery.

Towing advice in the car handbook was to drive with headlights on to make the alternator produce more power.

After a year of problems, I finally decided to fit a " battery to battery charger" in the van, this takes whatever is available from the car and puts out a suitable voltage to charge the van battery and run the fridge.  It can  be set to prioritise either battery or fridge, or share equally, I have it on battery priority.  It also prevents power being pulled from the van battery       Not had a problem with the battery since fitting it.  Fridge stays nice and cold too.

I seem to remember someone saying there was something that could be fitted in your car to help with the smart alternator problem, but no idea what it is.