hope you get a rock solid answer from someone with your unit. not all units come with a disconnect. should be either by the battery or maybe just inside the unit in a storage compartment up front (if you have one near the battery) I simply remove the negative as my disconnect.
Found it! Now I wonder why the system has stopped charging? Dirty solar panel?
Leave your disconnect on. I always check to make sure the battery is on by turning on the little light on the front of the trailer. Then you know you have power.