Electric problem trip switch won't switch on ????

Hi guys hope someone can help?
New here bought my first dandy a few weeks ago. 2007 Dimension... full circle from my Mum and Dads Dandy discovery (I think) back in 1978 happy memories.
So had the beauty up today to test everything for next weekends maiden voyage,h everything works fine except the 240v mains power,  can't check 12v as have no leisure battery, but i had it hooked up to the mains from the house using a riva bought 240v 3pin mains to blue plug running the power lead to the van. No power.! Checked the lead and power, everything fine but no power to the van. The strange thing though is that the RCD trip switch wouldn't stay in the on position not allowing any power to enter the trip switch box to trip any switches off if there is a problem.
Anybody out there who can help before I give Ian a Call tomorrow to ask for advice.
Strange thing is, I bought it of a lovely couple who only bought the dandy back in April off Riva direct, all paper work shows this (they sold due to unforeseen circumstances) so it did have a service before it was sold .
So I'm thinking this could be something and nothing....any help please.
Phill

Just seen this and probably you have already sorted it out. But if the RCD won't stay in the on position, then you have a problem in the wiring somewhere, with a leak to earth. Of course with the RCD in the off position, you could never get power to the sockets.
You would need to get someone with proper test equipment to check for you. Might just be water got in to the electrics somewhere.

Hi there sorry not replied, but thanks for your response.
Thankfully not a problem with electrics, just a faulty RCD which has now been replaced.
Thanks once again

If there is no power to the dandy the RCD trip switch will not stay in as a result of there being no power. It's a useful way to test to see if the power is on.

So this may be a problem with the house socket or the EHU lead or the fuse in the EHU lead 13Amp plug.

Or of course the RCD could be faulty but most likely lack of power is the cause.