Go to page 40
of this PDF Controls section.
The fridge on AUTO will find what is available if your on shore power cord it will be AC. Disconnect the AC it will go to LP.
If you want to you can force from AC to LP.
There is a fuse on control board that protects the electric elements if blown no way fridge will cool on shore power.
Control board is in pdf also plus trouble shutting section.
If its your first time operating you may have air in line for LP and it will have to cycle for start a few times to get air out even if you turned on stove to remove air in lines.
When your fridge starts cooling will take between 12 to 24 hours to get really cold.
Freezer will cool first, may notice frost, than box will cool down and you should hear fans in vent areas running if your in warm areas of country.
The mode will only light if you have 12v feeding fridge and if you have good AC & LP FEEDING THE FRIDGE.
It will only light when you press the button to indicate what mode its in and AC will take precedent.
Look above in stickies there is a recall on 1200 a sticky shows a picture of the fix which you should have on your fridge if not recall is free should get it fix could cause a fire if not done.