Air conditioning control

[sedelange]

I am moving from the wet locker to the space under the V berth to gain storage space.  The control for the unit is a Cruisair three knob panel with a bourdon tube and relay box.  I would like to replace the knobs with a programable thermostat sytem.  The retrofit kit from Cruisair is around $600.  I am considering building my own relay box.  Has anyone fabricated their on thermostat / relay system to replace the older control system?

Steve DeLange