NISSAN 2012 Armada - Owner's Manual - Manual (Page 376)

To use the engine block heater:
1. Turn the engine off.
2. Open the hood and unwrap the engine block
heater cord.
3. Plug the engine block heater cord into a
grounded 3-wire, 3-pronged extension
cord.
4. Plug the extension cord into a Ground Fault
Interrupt (GFI) protected, grounded 110-
volt AC (VAC) outlet.
5. The engine block heater must be plugged in
for at least 2 - 4 hours, depending on outside
temperatures, to properly warm the engine
coolant. Use an appropriate timer to turn the
engine block heater on.
6. Before starting the engine, unplug and prop-
erly store the cord to keep it away from
moving parts.
Starting and driving 5-39