My van has the wiring for all 4 jacks joined together somewhere in the walls (lovely !). This means that they all work together or not. This is insane thinking.

Its very unlikely that any camping location its going to have a perfectly even surface. 

Once off the vehicle tray, one needs to adjust each leg to make for a level van.

The way the van should have been wired, is for each jack to be independently wired to the controller, and each have an isolation switch to turn them on or off.

At the moment I do this by disconnecting the plugs at each jack. Its not the right method, as plug connectors have a very limited number of times they can be disturbed (they are not designed for this). The only option, short or rewiring all jacks externally around the van, is to fit an in-line switch in one wire at each jack.

Does anyone know of any in-line weather resistant 12Vdc switches?

Also, does anyone recognise the jack brand. No markings other than serial number (van came from China and their no-name massive factories will not respond back to me, unless perhaps I purchased 1000 vans or so).

they must all go back to a switch somewhere , can you separate them there or are they daisy chained ?

only other way would be to put a switch on each jack .

Hi. Thank you for the reply. They cannot be daisy chained (I'm an electrician). They join together inside a wall somewhere. Only one output connection from central controller to somewhere inside a wall.

Wire in both, all & bypass for each. Try RS online, they are a bit dear by it's free delivery & they are quick.

Hi mischief. Just measured a jack motor. Very surprisingly, each draws less than 1A (about 0.5A when running). I would have expected much more.
One Amp is nothing. I guess its why the jacks are geared to be so slow. The 6A switches I ordered will be fine, as I will not use them for load break function, just isolation.