The low point drains are on the downstream side of the water pump. The water tank is on the upstream side of the water pump. I can't tell you where either is located, but I can tell you they are NOT the same. The tank drain is usually right on the bottom of the tank, but there may be hose between the tank and the valve since you have a motor home.
1988 Coleman Sequoia - popup (1987-2007)
2012 Roo19 - hybid (2012-2015)
2016 Mini Lite 2503S - tt (2015 - ???)
2011 Traverse LT, 3.6L, FWD
2009 Silverado Ext Cab, 5.3L, 4x4, 3.73
2016 Silverado 2500HD Dbl Cab, 6.0L 4x4, 4.10