My Reich Motor Mover on a 2012 Troll failed and Truma said that they do not provide support for a product of this age! 
Was given the details of A&R Electronic Developments in Cannock (01543 274284) who built the Control Unit and who provide a repair service or replacement units for the electronics in Truma Motor Movers and Heaters as well as several other brands.
Following some advice from A&R managed to sorted out the problem myself.
Thought it was worthwhile sharing the details with the group as a repair could be cheaper than buying a new piece of kit from Truma.