how can i find a fault in my caravan electrics?

I have an ace aristocrat 490 and have just fitted a new lesiure battery on my van i have a powertouch mover this working fine but I cant get power through to the emi unit the battery reader is not showing any batt power nor is any lights coming on it all worked last year but since wintering I wont show any power going into the van I think it could be a fuse or an inline breaker can anyone tell me where all the main fuses are on this line I know all fuses for the outside lights are fine and working just the general electrics the interiour if anyone can help please contact me urgently