When Ambient Air Temps are below 50*F turn on the 'LAT' Switch (Low Ambient Temp) located on upper frame below control display panel
This will turn the interior light ON causing a 'heat load' which will cause longer cycles.
IF still having issue with low temp operation place a 60W light bulb backside of fridge via lower access panel
40*F is not real cold and shouldn't affect fridge cooling process but your fridge like so many was probably NOT installed with correct clearances as outlined in Dometic Installation Manual (which MANY RV MFGs ignore)
Also unplug/replug the 6 pin connector on lower circuit board top left corner (communication harness between lower/upper circuit boards)
making sure you have good tight contacts
Is it time for your medication or mine?
2007 DODGE 3500 QC SRW 5.9L CTD In-Bed 'quiet gen'
2007 HitchHiker II 32.5 UKTG 2000W Xantex Inverter
US NAVY------USS Decatur DDG31