As Bill Sprague indicates, hydronic pre-heat operates entirely different than a block heater, and misuse of terminology can confuse them. It's conceivable that Bill Jourdain has neither function, though I thought block heaters were routinely factory installed.
I can't speak to his 2002 Seacliff, but our '06 model has the optional hydronic preheat as well as the block heater, which is activated from a 12 volt switch among the driver's switch group, marked as Bill S. says. That relays to a 110v., 1800 watt block heating device that has a cord that plugs into a 20 amp GFCI outlet. The outlet may be powered by park power or the generator, but not off inverter function - like a refrigerator, it would quickly run down batteries. Forgive me, I don't recall precisely where my cord plugs into such an outlet, likely a protected engine compartment wall someplace; I've never used it since the HydroHot preheat does the job well, and is probably more efficient because it actually circulates warmed coolant throughout the engine.
A block heater would be used in subzero temps and might be left on overnight to have an effect, whereas hydronic preheat works in an hour or two, depending on ambient temps. and how warm you like the engine to get before starting; I prefer 100 degrees F as my owners manual suggests, though as Dick proffered, cold starts are certainly plausible if necessary. The engine's electronic Cold Mode limits power and idle to 800 RPM until engine coolant reaches 82 degrees.
If you can't find a dash switch, Bill, you might check the engine compartment for a heavy duty 110v. 15 amp power cord somewhere. It may not be actually plugged in, but rather coiled and tied out of the way, ready to plug into its dedicated coach outlet or an extension cord to an outside power source. Also look for a 15 amp breaker marked for the Block Heater on your 50 amp Main panel box.
Joel
