I don't know if your engine has a belt driven fan, if it does you may be hearing the fan clutch engaged which causes the fan to be loud. This will happen when starting out in the morning (for a few minutes) and when hot or going up a grade. On my truck it makes a whining sound.
For outdoor lighting I have a yard type light that hangs from my awning. It uses a 15watt CFL type bulb. The light has a dusk to dawn sensor. I use this light when we need bright lighting.
I've also added some of those solar power garden lights. I place a few around the RV in areas where we will be walking.
I have a 20 foot rope light that attaches to the channel on the roller end of the awning, this provides light similar to a full moon. Between this rope light and the solar garden lights there is good lighting for getting around but not bright enough to read or work by.
We also have two battery powered LED Lanterns....these are great, very bright and the batteries last a long time. They came in handy during a recent power outage that lasted for 18 hours. You can pick these up at Walmart, Target or outdoor supply stores.