Should be the same as the inside shower. Hot & cold taps with hose and shower head. You'll need either a city water hookup or water pump turned on inside to create the water pressure.
Check the switch on the shower head isn't turned off if nothings coming out.
We use ours just as much for filling up the dishpan as we do for a quick rinse off of our feet or after a swim.
2007 Shamrock F19 hybrid - 2010 (22 nights), 2011 (24 nights), 2012 (11 nights)
2013 Surveyor Select 235RKS - 2012 (6 nights), 2013 (32 nights), 2014 (26 nights), 2015 (37 nights), 2016 (14 nights)