Guess what, I finally found the power receptacle for the engine block heater.
In the electrical compartment, the aft bay on the driver's side, there is a black metal box attached to the ceiling of the compartment.
On the side you can see when you open the compartment there are two switches, Lights and Water Pump. Also, there are plugs for Telephone, Sat TV and Cable TV. The compartment light is on the bottom of this black box. The receptacle for the engine block heater is on the aft end of the black box. I needed a flashlight to see it.
Thanks all for your help.