Swift caravan electrical problems

[Stezla]

Hi there I'm hoping someone can help me - I bought a used swift challenger 640 recently (Year ? 2015) and have had an intermittent problem with the electrics which seems to have got worse/ more frequent ... the control panel and thuma heater and domestic fridge and internal lights go off occasionally without warning ( the plug sockets seem ok though and work fine ) and when I turn off the electric and back on there is a beep and the lights flash on the control panel, thuma panel and fridge momentarily but then disappear again. Very frustrating as im at a bit of a loss as to what to do - its on a seasonal pitch and I dont have a tow car anymore so can't take it easily to get someone to check it. Ive looked behind the back panel above the door and can't see any obvious problem with the wiring( although there are a few wires with connections which are not plugged in- but these could not have been plugged in since I had the van and as I say it does work sometimes and for quite a while when it is is all fine - My vague diagnoses are:
1 an intermittent problem with the control panel (unlikely I guess but I could order a new one to replace it and check )
2 a problem with the fridge - (maybe when it has been on for a time could it short the system maybe? I did have a problem with my home fridge when dust collected at the back by the condenser after a time ) but I dont really know how to move the fridge out and I dont want to yank it out and break it
it seems to light up control panel , then thuma panel then fridge then goes off
Ive attached some photos - im hoping someone sees this and has a simple solution to my problem and would be grateful of any help or ideas Thanks Phil

 

[toad a caravan]

Have you cured the problem yet...Gary