Stock Block Heater Issues

Ok so the weather up heres starting to get crappy and i tried using the block heater, which i have now found out doesent work at all. Iv read the other threads on this site but am still confused as to where the block heater is. It sounded to me that it is locaited in the upper left corner, attached in the firewall. When i follow the power cord from the front of the truck it goes right into the engine block, whats up with this. Im so lost, someone help me find this stupid thing.

check drivers side engine block under the manifolds you will see a freeze plug with a cord attatched to it, bingo