Outside switch ONSO it is a Suburban Water Heater....outside switch is for electric & inside switch is for propane
120V AC........Black wire
12V DC (propane)...Red wire
Suburban uses a simple wiring scheme for their 'standard' water heaters
120V AC
Individual Circuit Breaker feds AC Hot/Common to junction box on right side of tank looking at WH Tank from inside RV)
From Junction Box to ON/OFF switch (Black Wire)
From On/Off Switch AC Power goes to the set of T-stats (Left side Black Wire=----top t-stat is HI temp with manual Push to Reset)
From Set of T-stats AC Power goes to Element (Black Wire)
Neutral goes from element back to AC Power Panel (White Wire)
