Hi Antony & Dee,
Thanks for the PDF, I will try and post it in the technical section for the benefit of other members.
Having studied the PDF and other relevant information on the Dometic charging setup, I am trying to narrow down what will be the most likely cause of the problem, with the lowest cost solution.
With regard to the radio reception problem as mentioned by Steve and Maureen above, I had initially suspected the well documented reception problem in a Fiat type Hobby, where the aerial is fitted within the nearside door mirror, but this is not the case.
It would seem by the post I have linked to below that the main problem in a Renault conversion is the inferior quality receiver as fitted by the manufacturer.