The block heater on a 2006 Ford Ranger 3.0L is located
in the engine block, on the driver's side (left side when looking at the engine from the front of the vehicle). It's usually near the thermostat housing, but its exact position might vary slightly. You'll see a cord extending from it that goes to an exterior electrical outlet.
It's a good idea to visually inspect your engine block near the thermostat housing with a flashlight to locate the cord. If you cannot find it easily, consult your owner's manual or a repair manual specific to your vehicle.
