Vehicle power supply and fridge issues

I vaguely recall a similar issue linked to vehicles fitted with smart alternators and regenerative braking - explained here 12V Planet

You have to specify a separate fridge feed for most cars when using dedicated electrics as european manufacturers don't include them in the electrics module.

Back in the day the towbar electrics also used to include a device that only fed the caravan fridge when the car battery was suitably charged. This ensured the car battery had priority after starting, though that was in the days when less powerful alternators were fitted.

Thanks.  I hadn't investigated before just how much they draw.  Now there's food for thought (or should it be "food going off") when using one of the longer ferry crossings.

What food? By all accounts, you won’t be taking anything that'll go off.

As long as you keep the door shut, the fridge will stay cool enough.

The 'small' fridge in my previous caravan drew around 10A, so at best (even if you could get your caravan fridge to run off the leisure battery)  it'd only run for half a day from a large battery

I haven't read through all the replies so this may have already been pointed out. Although you have a 13 pin plug, the 12 volt supply to the fridge, and a permanent 12 volt for ATC is an option. They are expensive extras so may not have been connected.  

Whilst slightly off topic i thought i might mention a power supply issue with the three way fridge  in my Pegasus GT65 that i encountered last summer. Having been a caravanner for 28 years i am slightly embarrassed to mention it but- The 240v power supply for our dometic fridge (and cooker) is via a switched 3 pin plug and socket in the pan storage area under the adjacent cooker.  In putting a pan away i accidentally pushed the switch into the off position resulting in the fridge being off overnight. When we realised the 240v wasnt working we switched to gas.  We eventually discovered the simple solution when we got home.  Check the obvious first!     

It is only certain continental manufacturers that regard these as an option and why people put up with it is beyond me, I have never had to beg for additional wiring on any of my Land Rovers. As for the permanent 12v supply, that has been around as long as I can remember originally as 12s pin 4 and certainly long before ATC was invented.