Dodge Dakota (R1). Manual - part 790
If the floor outlet air temperature is too low, refer
to Cooling to check the engine coolant temperature
specifications. Both of the heater hoses should be hot
to the touch. The coolant return heater hose should
be slightly cooler than the coolant supply heater
hose. If the return hose is much cooler than the sup-
ply hose, locate and repair the engine coolant flow
obstruction in the cooling system. Refer to Cooling
for the procedures.
OBSTRUCTED COOLANT FLOW
Possible locations or causes of obstructed coolant
flow:
• Faulty water pump.
• Faulty thermostat.
• Pinched or kinked heater hoses.
• Improper heater hose routing.
• Plugged heater hoses or supply and return ports
at the cooling system connections.
• A plugged heater core.
If proper coolant flow through the cooling system is
verified, and heater outlet air temperature is still
low, a mechanical problem may exist.
MECHANICAL PROBLEMS
Possible locations or causes of insufficient heat:
• A faulty blower system.
• A faulty heater-A/C control.
• An obstructed cowl air intake.
• Obstructed heater system outlets.
• A faulty, obstructed or improperly installed
blend-air door or actuator.
TEMPERATURE CONTROL
If the heater outlet air temperature cannot be
adjusted with the temperature control knob on the
a/c heater control panel, the following could require
service:
• The a/c heater control.
• A faulty blend door actuator.
• The blend door.
• Improper engine coolant temperature.
• Obstructed cowl air intake.
Heater Diagnosis
CONDITION
POSSIBLE CAUSE
CORRECTION
INSUFFICIENT HEATER
OUTPUT.
1. Incorrect engine
coolant level.
1. Check the engine coolant level. Refer to Group 7 -
Cooling System for the procedures.
2. Air trapped in engine
cooling system.
2. Check the operation of the coolant reserve/recovery
system. Refer to Group 7 - Cooling System for the
procedures.
3. Incorrect engine
coolant temperature.
3. Check the performance and operation of the engine
cooling system including: thermostat, water pump, fan
drive, accessory drive belt, coolant flow (plugged radiator
or heater core, plugged or kinked coolant hoses), air flow
(missing or improperly installed radiator air seals or fan
shroud). Refer to Group 7 - Cooling System for the
procedures.
4. Blend air door
actuator not operating
properly.
4. See Blend Door Actuator in the Removal and
Installation and in the Adjustments sections of this group.
5. Blend-air door not
operating properly.
5. Check for a damaged, obstructed or improperly
installed blend-air door or seals. See Heater-A/C Housing
Door in the Removal and Installation section of this
group.
6. Insufficient air flow
through heater housing.
6. Remove foreign material or obstructions from cowl air
intake.
7. Improper blower motor
operation.
7. See Blower Motor in the Diagnosis and Testing section
of this group.
8. Improper electric
coolant pump operation.
8. See electric coolant pump section of this group.
24 - 6
HEATING & AIR CONDITIONING
AN
HEATING & AIR CONDITIONING (Continued)