Greetings from Auckland, New Zealand.

[JafaJones]

HI thanks for the photos , however they are slightly out of focus (the camera has focused on the orange wires, not the terminals) also can you take photos of the underside of the board( track side) as the this will confirm your assumptions about the connections (and also allows me to add to my files on charger/PSU's) , which reading through your analysis appears correct. I have attached a schematic of the existing charger wiring and for a new battery charger module.Unfortunately this forum does not allow pdf files to be uploaded so I have had to convert the file to a jpg which has lost some of the resolution.
There is another forum called caravantalk.co.uk/forum which does allow pdfs so if you join that forum I will post the pdf on it if you are struggling to see it clearly

Thanks again Ian, The only way to get at the back of the underside of the board is to disassemble the charger and am a bit reluctant to do this at this stage but no probs, your image is fine. I will roll my sleeves up and hopefully get this saga sorted out.
The wire numbers on your schematic appear to correspond to those on my block diagram or is that just a coincidence?
BTW had previously joined CaravanTalk during my earlier searching around.
Regards
Mike

 

[IanB1485]

I generated my schematics from your description so no it wasn't a coincidence , also I have photos of similar ( but older chargers) so the 12V terminals layout is pretty similar