Couple of things:
Only run fridge when RV is level wen stationary (OK while in transit)
Fridge should be a electric/propane unit
Model number of fridge will get full details
Did you get a packet of manuals/pamphlets when you purchased the Roadtrek?
Should have and should be decent info about the various systems/appliances etc.
Norcold 5 cu ft fridge is probably an 'N510/N512' model
Here is manual that covers it
If not that model...post which one you have