Caravan shock when touching earth and van

Yes.

It isnt static, everytime you touch it, you get a boot. Its got to do with grounding or/and power box supply not earthing properly. Iv tested what i can without going further. Appliences in van wont work properly either like a/c. im going with the bet it is in supply system. as we hook up to station/rural power, not may eleckys will come out to such remote locations. we have been trying to get hold of one with no luck. typical.

Get a volt meter and run in from where you are getting shocked to ground. You should see a voltage signal on the meter if you are getting consistently shocked. Turn all your breakers off, then turn them on one at a time to see when the signal comes back. That should get you started as to where the problem is.

I second engineer.

You said you had rains. You might have a leak which allowed water to collect and short out something. It may go away when you dry out but you probably want to track it down or it will come back.