I've struggled to find a manual
It's not really worth spending time on the controller, it will work or it's broken.
Since the caravan is new to you, it's possible the battery is past its best. You should have documentation on the vans 12v system or it will be online. Often its a simple charger/ power supply operating from AC with a small 12v battery for lighting, water pump.
The solar and panel have most likely been fitted by a previous owner.
I suggest some simple tests on the battery and panel. You need a multimeter.
A battery is resionable condition will have a voltage greater than 12.6 after charge but at rest, no load or charge.
The solar panel, disconnect from the controler should, with sunlight, show a voltage in the region of 20 volts. When connected to the controller, the volts will fall to just higher than battery volts. If the controler and panel are operational, the battery volts will increase to over 14 volts as the battery is charged.
The load outputs on this type of controler are intended to drive low power 12v lights. I guess the programming buttons determine how these outputs operate. Usual options are, on continously, off, or on when it's dark.
In most RV applications, 12v stuff is normally powered of the battery, not the load outputs.
In many situations where you become the owner of previously installed electrical equipment that's not working and poor quality, it's better to start over with new.
Perhaps if you outline your requirements, then advice on proceed can be discussed.
Mike
