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.

24 - 6

HEATING & AIR CONDITIONING

ZB

HEATING & AIR CONDITIONING (Continued)

SPECIFICATIONS

HEATING-A/C SYSTEM

A/C SYSTEM

Item

Description

Notes

A/C Compressor

Denso 10S17C

ND-8 PAG oil

Freeze–up Control

A/C low pressure switch

Accumulator mounted - input to
powertrain control module (PCM) -
PCM opens compressor clutch
relay below 131-141 kPa (19-21
psi), closes relay above 241-269
kPa (35-39 psi)

Low psi Control

A/C pressure transducer

Discharge line mounted - input to
powertrain control module (PCM) -
PCM opens compressor clutch
relay below 110 kPa (16 psi),
closes relay above 220 kPa (32
psi)

High psi Control

A/C pressure transducer

Discharge line mounted - input to
powertrain control module (PCM) -
PCM opens compressor clutch
relay above 3219 kPa (476 psi),
closes relay below 2937 kPa (426
psi)

Refrigerant Charge Capacity

Refer to the A/C Underhood Speci-
fication Label located in the engine
compartment

R-134a refrigerant

A/C Clutch Coil Draw

3.3 amps

@ 12V± 0.5V @ 21 ° (70° F)

A/C Clutch Coil Resistance

3.6 ohms

When measured across the coil
lead connector

A/C Clutch Air Gap

0.35 - 0.60 mm (0.014 - 0.024 in.)

ZB

HEATING & AIR CONDITIONING

24 - 7

HEATING & AIR CONDITIONING (Continued)

FASTENER TORQUE

Description

N·m

Ft. Lbs.

In. Lbs.

All Screws NOT Listed
Below

2

–

17

A/C Compressor Clutch
Bolt

17.5

–

155

A/C Compressor Mount-
ing Bolts

23

17

–

A/C Condenser to Radia-
tor Bolts

5

–

45

A/C Discharge Line to
A/C Condenser Bolt

18

13

–

Accumulator Mounting
Bracket Nuts

5

–

45

HVAC Housing to Dash
Panel Bolts

7

–

60

HVAC Housing to Dash
Panel Nuts

7

–

60

Liquid Line to A/C Con-
denser Bolt

18

23

–

Refrigerant Lines to Evap-
orator Nuts

13.5

10

–

Refrigerant Lines to Com-
pressor Bolts

25

18

–

Suction Lines to Accumu-
lator Bolts

18

13

–

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HEATING & AIR CONDITIONING

ZB

HEATING & AIR CONDITIONING (Continued)

CONTROLS

TABLE OF CONTENTS

page

page

A/C COMPRESSOR CLUTCH

DESCRIPTION

. . . . . . . . . . . . . . . . . . . . . . . . . . 9

OPERATION

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

DIAGNOSIS AND TESTING

A/C COMPRESSOR CLUTCH COIL

. . . . . . . . 10

STANDARD PROCEDURE

A/C CLUTCH INSPECTION

. . . . . . . . . . . . . . 11

A/C CLUTCH BREAK-IN

. . . . . . . . . . . . . . . . 11

REMOVAL

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

INSTALLATION

. . . . . . . . . . . . . . . . . . . . . . . . . 13

A/C COMPRESSOR CLUTCH RELAY

DESCRIPTION

. . . . . . . . . . . . . . . . . . . . . . . . . 14

OPERATION

. . . . . . . . . . . . . . . . . . . . . . . . . . . 14

REMOVAL

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

INSTALLATION

. . . . . . . . . . . . . . . . . . . . . . . . . 14

A/C HEATER CONTROL

DESCRIPTION

. . . . . . . . . . . . . . . . . . . . . . . . . 15

REMOVAL

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

INSTALLATION

. . . . . . . . . . . . . . . . . . . . . . . . . 15

A/C LOW PRESSURE SWITCH

DESCRIPTION

. . . . . . . . . . . . . . . . . . . . . . . . . 16

OPERATION

. . . . . . . . . . . . . . . . . . . . . . . . . . . 16

DIAGNOSIS AND TESTING

A/C LOW PRESSURE SWITCH

. . . . . . . . . . . 16

REMOVAL

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

INSTALLATION

. . . . . . . . . . . . . . . . . . . . . . . . . 17

A/C PRESSURE TRANSDUCER

DESCRIPTION

. . . . . . . . . . . . . . . . . . . . . . . . . 17

OPERATION

. . . . . . . . . . . . . . . . . . . . . . . . . . . 17

DIAGNOSIS AND TESTING

A/C PRESSURE TRANSDUCER

. . . . . . . . . . 18

REMOVAL

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

INSTALLATION

. . . . . . . . . . . . . . . . . . . . . . . . . 18

BLEND DOOR ACTUATOR

DESCRIPTION

. . . . . . . . . . . . . . . . . . . . . . . . . 19

OPERATION

. . . . . . . . . . . . . . . . . . . . . . . . . . . 19

REMOVAL

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

INSTALLATION

. . . . . . . . . . . . . . . . . . . . . . . . . 20

BLOWER MOTOR RELAY

DESCRIPTION

. . . . . . . . . . . . . . . . . . . . . . . . . 20

OPERATION

. . . . . . . . . . . . . . . . . . . . . . . . . . . 20

REMOVAL

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

INSTALLATION

. . . . . . . . . . . . . . . . . . . . . . . . . 21

BLOWER MOTOR RESISTOR BLOCK

DESCRIPTION

. . . . . . . . . . . . . . . . . . . . . . . . . 21

OPERATION

. . . . . . . . . . . . . . . . . . . . . . . . . . . 21

DIAGNOSIS AND TESTING

BLOWER MOTOR RESISTOR

. . . . . . . . . . . . 22

REMOVAL

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

INSTALLATION

. . . . . . . . . . . . . . . . . . . . . . . . . 23

MODE DOOR ACTUATORS

DESCRIPTION

. . . . . . . . . . . . . . . . . . . . . . . . . 23

OPERATION

. . . . . . . . . . . . . . . . . . . . . . . . . . . 23

REMOVAL

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

INSTALLATION

. . . . . . . . . . . . . . . . . . . . . . . . . 24

RECIRCULATION DOOR ACTUATOR

DESCRIPTION

. . . . . . . . . . . . . . . . . . . . . . . . . 24

OPERATION

. . . . . . . . . . . . . . . . . . . . . . . . . . . 24

REMOVAL

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

INSTALLATION

. . . . . . . . . . . . . . . . . . . . . . . . . 25

A/C COMPRESSOR CLUTCH

DESCRIPTION

The A/C compressor clutch assembly consists of a

stationary electromagnetic A/C clutch field coil, a pul-
ley bearing and pulley assembly, and a clutch plate
(Fig. 1). These components provide the means to
engage and disengage the A/C compressor from the
engine accessory drive belt.

The A/C clutch field coil and the pulley bearing

and pulley assembly are both retained on the nose of
the A/C compressor with snap rings. The clutch plate
is splined to the compressor shaft and secured with a
bolt.

OPERATION

The A/C compressor clutch components provide the

means to engage and disengage the A/C compressor
from the engine accessory drive belt. When the elec-
tromagnetic A/C clutch field coil is energized, it mag-
netically draws the clutch plate into contact with the
clutch pulley and drives the compressor shaft. When
the coil is not energized, the pulley freewheels on the
clutch hub bearing, which is part of the pulley.

The A/C compressor clutch engagement is con-

trolled by several components: the A/C-heater control
in the passenger compartment, the A/C pressure
transducer on the discharge line, the compressor
clutch relay, the A/C low pressure switch on the accu-

ZB

CONTROLS

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