Dodge Viper SRT-10 (ZB). Manual - part 258
HEATER PERFORMANCE
Before performing the following tests, refer to
Group 7 - Cooling for the procedures to check the
engine coolant level and flow, engine coolant reserve/
recovery system operation, accessory drive belt condi-
tion and tension, radiator air flow and the fan drive
operation. Perform the A/C System Performance Test,
which is found within this group. If any diagnostic
trouble codes (DTCs) are found in powertrain control
module (PCM), repair as necessary.
MAXIMUM HEATER OUTPUT
Engine coolant is delivered to the heater core
through two heater hoses. With the engine idling at
normal operating temperature, set the temperature
control to the full hot position, the mode control to
the floor position, and the blower motor control to the
highest speed position. Using a test thermometer,
check the temperature of the air being discharged at
the front floor outlets. Compare the test thermometer
reading to the Heater Temperature Reference chart.
HEATER TEMPERATURE REFERENCE
Ambient Air Temperature
15.5° C
(60° F)
21.1° C
(70° F)
26.6° C
(80° F)
32.2° C
(90° F)
Minimum Air Temperature at
Floor Outlet
52.2° C
(126° F)
56.1° C
(133° F)
59.4° C
(139° F)
62.2° C
(144° F)
If the heater outlet air temperature is below the
minimum specification, refer to Group 7 - Cooling.
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 supply hose,
locate and repair the engine coolant flow obstruction
in the cooling system. Refer to Group 7 - Cooling for
more information.
OBSTRUCTED COOLANT FLOW
Possible locations or causes of obstructed coolant
flow are as follows:
• 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.
• Plugged heater core.
If proper coolant flow through the cooling system is
verified, and heater outlet air temperature is low, a
mechanical problem may exist.
MECHANICAL PROBLEMS
Possible locations or causes of insufficient heat due
to mechanical problems are as follows:
• Obstructed cowl air intake.
• Obstructed heater system outlets.
• Blend-air door or actuator not functioning prop-
erly.
• Faulty blower motor system
• Faulty A/C-heater control
TEMPERATURE CONTROL
If the heater outlet air temperature cannot be
adjusted with the temperature control on the A/C-
heater control, the following could require service:
• Faulty A/C-heater control.
• Faulty blend door actuator.
• Faulty, obstructed or improperly installed blend-
air door.
• Faulty related wiring harness or connectors.
• Improper engine coolant temperature.
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HEATING & AIR CONDITIONING
ZB
HEATING & AIR CONDITIONING (Continued)