Where is the slow fuse in Truma avenue plus

Hi there

My motorhome (Malibu440LE) was already fitted with a Truma aventa plus air conditioner  when I bought it, Unit suddenly stopped functioning and it seems it is a fuse problem. Truma says there is a 6.3A slow fuse in the electronic control unit which is user replacable. Now my question is where is this unit and how shall I access it, From inside? From the roof?Any help would be greatly appreciated.

Many thanks

Muratti