HEATER AND AIR CONDITIONING 1A-69
Fig.
96—Refrigerant and Vacuum Hoses (Corvette)
2.
Mount the sensor to the dash and connect the wires
to the Comfortron harness.
3.
Replace glove box assembly.
Control Head
The control head is attached to the instrument panel
flange in the same manner as the Four Season Control
Panel (See Figure 105). Two screws hold the head in
place. The amplifier, blower switch and servo and
defrost control cables are all part of the control head.
Amplifier
After the control head is removed from the instrument
panel, the amplifier may be removed as shown in Figure
107.
Temperature Dial Adjustment
1.
Install Tester J-22368 as previously described.
2.
Set Tester Voltage switch to Control Calibrate
position.
3.
Start the engine (fast idle) and set Comfortron
Control lever to HI-FRONT.
4.
Switch Rocker switch to MANUAL.
5. Set Manual Control Knob to 150 ohms on scale.
6. Rotate the Control Head Temperature Dial until the
voltmeter on the tester reads 6.5 volts. The Tem-
perature Dial should now indicate 75°.
7. If the Temperature Dial does not indicate 75°, insert
Tool J-21530 in slot to the left of the Dial as shown
in Figure 106.
8. With tool in position, rotate the Temperature Dial
so that it indicates 75°F.
Transducer
Figure 104 illustrates the installation of the transducer
assembly. Vacuum lines are clamped to the transducer
vacuum ports.
Fig.
97—Comfortron Vacuum Tank
CHEVROLET CHASSIS SERVICE JWANUAl
HEATER AND AIR CONDITIONING 1A-70
Fig.
98—Comfortron Thermal Vacuum Valve
Power Servo .
The Power Servo is attached, to the distributor duct.
The entire installation consists of the Servo Assembly
and its link assembly to the TEMP door. The Servo is
attached to the Air Selector Duct as shown in Figure 108.
Mode Shift Vacuum Diaphragm
Replacement
1.
Remove the heater distributor from the vehicle.
2.
Reach into the distributor through the AIR door
opening to reach and remove the vacuum diaphragm
mounting screws and diaphragm to door link screw
(remove piug from case to reach this screw).
3.
Reverse this procedure to replace.
4.
Adjust mode door without vacuum applied to dia-
phragm. The door should be open one inch from
sealing against the air distributor opening (inside of
case).
(Figure 109).
HIGH BLOWER
DELAY RELAY
.MASTER
DELAY
RELAY
Fig.
100—Comfortron Relays
COLLISION PROCEDURE-AII Systems
Whenever a car equipped with air conditioning unit is
involed in a collision or wreck, it should be inspected as
soon as possible. The extent of damage to any or all of
the component parts and the length of time the system
has been exposed to the atmosphere will determine the
replacement of parts and processing that will be re-
quired. The greater the length of time of exposure to the
atmosphere, the greater will have been the chances for
air, moisture and dirt to have entered and damaged the
system. Every case may be entirely different so it is not
possible to establish a hard and fast procedure to follow
each time. Good judgment must be used to determine
what steps should be taken in each specific case.
The following procedure is presented as a guide for
Fig.
99—Comfortron Resistor Assembly
Fig.
101—Comfortron Sensor Installation
CHEVROLET CHASSIS SERVICE MANUAL
HEATER AND AIR CONDITIONING 1A-71
SUN-AMBIENT
SENSOR AND COMPRESSOR
CLUTCH SWITCH
HIGH BLOWER
DELAY RELAY
THERMAL
VACUUM
VALVE
Fig.
102-Comfortron Underhood Wiring
use when inspecting a damaged vehicle equipped with air
conditioning.
1.
Remove the drive belt. Cut belt off if necessary.
2.
Visually inspect the condenser, receiver-dehydrator,
compressor, mounting brackets, conditioning unit, all
connecting lines, and all controls to determine the
extent and nature of the damage.
a. No repairs, such as soldering, welding or braz-
ing, should be attempted on the condenser be-
cause of its construction. If the vapor passages
in the horizontal tubes or return bends or mani-
folds have been damaged in any way, the con-
denser should be replaced with a new one.
b.
The receiver-dehydrator should be replaced if
there is any evidence of its having sustained
either internal damage or a fracture at any of
the lines or welded joints or if the system has
been exposed to the atmosphere for an undeter-
mined period of time.
c. Examine the compressor for any visible external
damage.
d. The evaporator should be examined for damage
and, if necessary, removed or replaced or the
entire unit processed where damaged or exposed
to the atmosphere.
e. All connecting lines and flexible hoses should be
examined throughout their entire length for dam-
age.
If damaged in any manner, replace with new
lines.
f. Check all controls and connecting wires for
damage and replace with new parts where needed.
g. Check the clutch pulley for proper operation and
freedom from damage.
3.
Install gauge set.
4.
Purge the system. Pressure should not exceed 3 to
5 pounds.
5. Remove the compressor from mounting and remove
the oil test fitting.
6. Pour out the oil into a clean glass container and ex-
amine it for any foreign substance such as dirt,
water, metal particles, etc. If any of these are
present, the compressor and receiver-dehydrator
should be replaced and the other system components
should be flushed with liquid refrigerant.
7. If the oil is clean and free of any harmful substance,
replace oil with Frigidaire Oil available through
Parts Stock.
NOTE:
If the system components have been
replaced or flushed, replace the full charge of
oil. If not, add no more fresh oil than was
drained in Step 6.
8. Charge up the compressor to drum or can pressure
and leak test the compressor seals prior to in-
stallation of compressor.
9. Reinstall the compressor and evacuate the system
by following the Evacuating Procedure.
CHEVROLET CHASSIS SERVICE MANUAL
ACCESSORIES
15-6
port thereby supplying vacuum to the Servo unit.
During system operation
the
following events occur:
1.
Car
speed below
20
mph—no function
of the
unit
because
the
rubber drum
has
not rotated
far
enough
to close
the
solenoid points.
No
energizing current
can flow through the solenoid coil.
2.
Car
speed above
20
mph—The tang
on the
rubber
drum
has
closed
the
solenoid points
and
current
is
flowing through
the 40 ohm
resistance wire
to the
solenoid coil. This current
is
not sufficient to "pull
in", the solenoid.
3.
Driver partially presses Engagement Switch—full
voltage flows through
the
solenoid
to
pull
it
into
operation. Solenoid
cam
tension
on the "U"
clip
is
released and the clip grips the rubber drum. Simul-
taneously the vacuum switch operates; applying man-
ifold vacuum
to the
Servo unit which tightens
the
throttle chain. When
the
driver releases pressure
from
the
accelerator pedal
the
unit will position the
throttle
to
maintain the speed
at
the time
of
solenoid
operation.
Driver releases
the
Engagement Switch—current
flows
to the
solenoid through
the 40
ohm wire and
since the solenoid is "pulled in", the reduced current
flow
is
sufficient to hold
it
in position.
The
car
begins
to
ascend
a
hill—car speed drops
slightly (very slightly) and the magnetic force on the
driven disk
of the
speed sensor
is
decreased.
The
disk rotates slightly
(as
would
a
speedometer shaft
because
of
hairspring tension) turning
the
rubber
drum. Since
the "U"
clip
is
gripping
the
drum,
it
moves
the
slide which COVERS
the air
bleed ports
more. With less air bleeding into the Servo, greater
vacuum exists
in it
and the diaphragm moves toward
the vacuum port opening
the
throttle wider.
The
tapered needle moves into the orifice further and the
diaphragm balances
in a
new position with the wider
throttle opening.
Car
speed
has
been maintained
automatically.
1.
Speedometer Cable
Adapter (From
Transmission)
2.
Gasket
3. Speedometer Cable
Adapter
(To
Speedometer)
4.
Adapter
and
Magnet
Housing
5. Rotating Magnet
6. Helical Ramp
7. Field Plate Adjusting
Pinion
8. Adjusting Pinion
Locating Spring
9. Brass Magnetically
Driven Disk
10.
Field Plate
11.
Hair Spring
12.
Hair Spring Keeper
13.
Rubber Drum
Tang
14.
Rubber Drum
1$.
"U"
Shaped Clutch
Spring
16.
Air
Bleed Sleeve
17.
Orifice Tube
18.
Orifice
19.
Orifice Tube Locknut
20.
Clutch
and
Solenoid
Housing
21.
Vacuum Supply Port
(To Servo)
22.
Vacuum Port (To
Intake Manifold)
23.
Vacuum Valve Slide
24.
Solenoid Coil
25.
Solenoid Plunger
Return Spring
26.
Solenoid Cover Gasket
27.
Air Filter
28.
Solenoid Cover
29.
Air Inlets
Fig.
9-
Regulator
-
Exploded
CHEVROLET CHASSIS SERVICE MANUAL