In article .com,
Mel wrote:
Thin purple, medium length
Thick red, long length
Thick green, short length, with 15A inline fuse
Thin black, short length
Thick green, long length

If anyone has an idiot's guide to installing this unit I would be
very thankful for a copy.

It's a relay with SPDT contacts, at a guess.

The two thin wires will be the relay coil. I'd guess the green with the
fuse will be common, but to be certain you'll need some form of continuity
tester like an ohm meter and check which two contacts are made with the
coil off and energised.

How is it meant to work? Does it simply run the fridge off the car battery
with the engine running, and revert automatically to the caravan battery
when it isn't?

Sorry not to know, but I'm not a caravan person. ;-)

If so, I'd guess the green with fuse goes to the fridge, thick red to car
battery, and thick green to caravan one. But that's only the way I'd make
the colours - to be certain you'll need to test first.

The thin black to ground, and the thin purple to an ignition controlled
supply.

--
*How much deeper would the oceans be without sponges? *

Dave Plowman London SW
To e-mail, change noise into sound.