What are the lights?

I have an older Kenmore 12.8 freezer, obtained 2nd hand with no manuals. There are 3 lights (L to R - amber, green, red) and a switch on the lid. Can anyone tell me what they're for?

I cannot find any manual or information on the 3 lights. I would assume that the green light means everything is OK, the red means current problem, and the amber means manual defrost is due. Sorry, this is the best I can do. Later.