Are the electrical problems are on the habitation side? (been there, etc!) If so you will need a wiring diagram from the converter rather than one for the base vehicle. If you post up your model you may be lucky and someone on here will have one otherwise you may be better to join the owners club if there is one for your model, or a forum such as Motorhomefacts which caters for all conversions.
My apologies for 'assuming'; I previously had a 1998 petrol Talbot (same van) and all my wiring problems were with the bits Autohome had modified.
When I had my van I obtained a manual from Russek publications; electrical diagrams are included for the unconverted base vehicle (hence my previous comment)