Here is a very rough sketch of the wiring changes needed to use the controller when the fridge is running on DC. Note the fans only operate when the compressor is running and they run on power derived from the compressor supply.
Note that the fans must not be connected to earth because one side of the compressor AC supply is connected to earth.
I'll redraw it when I get back next week and I'll draw up the changes needed to run the controller when the fridge is running on AC or DC.
http://www.aulro.com/afvb/attachment...1&d=1421845019