thanks Ray, maybe I need to run a cable from the fuse box.

Very clever piece of kit that! I didn't know such thing existed. Here's a fixed link: http://www.ebay.co.uk/itm/2305022319...%3AMEBIDX%3AIT

We leave for France today, and I'll just have to remember to plug in/unplug the cooler. Shame its not already switchable. Alas I haven't got the time or inclination to wire it up to be switchable, as convenient as that would be.

Bon voyage!