Ron, I have an older Dometic RM 2200a, my manual says:
"12. REGULATION OF TEMPERATURE
With the appropriate thermostat knob set at number 3 or 4, the cabinet
will automatically meintrin a suitable temperature for ordinary food
storage. Usually, no further adjustment will be needed, but in hot
weather, or when more cooling is required, the knob must be turned to
a higher figure. If less cooling is required, the knob should be turned
to a lower figure."
Hope this helps...
Former 83 Burro Owner (destroyed in fire)
Looking for a new Fiberglass Project Trailer in New England.