Welcome Quest15 to irv2.
Without knowing what mode and age, have you checked the light holder for 12V and checked the door switch for its function while measuring the 12V.
Also may want to check to see if you have the necessary 12V for operation behind the fridge in vent area.
Check the wire leads to control board for dirty or loose connections and you said not sure if the fridge is cooling, check around the cooling coils for a yellow substance make sure your not loosing the cooling coils.
If you look at this PDF
will show light circuit #6 on drawing near bottom of PDF.