OPERATOR'S MANUAL

STARTING AND OPERATING THE VEHICLE
Medium Duty
(R05/09) Y53-6027 – 93 –
Engine Block Heater (Option)
To preheat the engine before starting, plug the optional
engine block heater into a properly grounded AC electrical
source. Do not start the engine with the heater plugged in.
WARNING! Engine block heaters can cause
fires resulting in death or serious personal
injury and/or property damage if not properly
maintained and operated. Regularly inspect
the engine block heater wiring and connector
for damaged or frayed wires. Do not use the
heater if there are any signs of problems. Con-
tact your Authorized Service Center or the
manufacturer of the heater if you are in need
of repairs or information.
CAUTION: Always unplug the heater before
starting the engine. Damage to the cooling
system could occur if the heater is not turned
OFF (unplugged).
When the temperature falls below 0°F (–18°F) for Cater-
pillar engines, or –10°F (–24°C) for Cummins engines, the
block heater is required.
• Use a solution of half ethylene glycol antifreeze and
half water for best heater performance. Do not exceed
60 percent concentration of antifreeze, as it can
shorten heater life. See page 146 for more informa-
tion.
• After servicing the cooling system, operate the vehicle
for a day or two before using the heater. Trapped air
inside the engine needs time to escape.
Cold Weather Starting—Air Intake Heater
Do not use ether or any other starting fluid as a cold start-
ing aid in your Medium Duty vehicle. Engine conditions
are automatically monitored and in cold weather the fuel/
air mixture is preheated in the manifold.
WARNING! Do not use ether or other starting
fluids as a cold-starting aid in your Medium
Duty vehicle. Your engine uses either an elec-
trical grid or an open flame inside the mani-
fold, to heat the air/fuel mixture for cold
weather starting. If ether or another starting
fluid is used, the air/fuel will ignite inside the
manifold, which could cause an explosion and
death or severe injury.