CONDITION POSSIBLE CAUSES CORRECTION
INADEQUATE HEATER PERFOR-
MANCE. GUAGE MAY OR MAY
NOT READ LOW.
1. Heavy duty cooling system, and
cooler ambient temperatures.
1. None. Normal condition.
2. Obstruction in heater hoses. 2. Remove hoses, remove obstruc-
tion.
3. Water pump damaged. 3. Replace water pump.
HEAT ODOR 1. Damaged or missing drive line
heat shields.
1. Repair or replace damaged or
missing heat shields.
2. Thermal viscous fan drive dam-
aged.
2. Check thermal viscous fan drive.
(Refer to 7 - COOLING/ENGINE/
FAN DRIVE VISCOUS CLUTCH -
DIAGNOSIS AND TESTING)
7 - 4 COOLING VA