Not quite the same unit, but mine are in two places - left rear corner, underneath near rear jack. Other one is inside passenger side baggage compartment, left side wall - there's a small panel with two screws you have to remove to see them. BTW - it took me two years to figure out that the valves pull up to drain - not just a turn.
2012 Ford F-150 Eco, Max/Max
Jayco 26.5 RLS, Reese Sidewinder