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AIR CONDITIONING
24-1 1
position NO. 3 and
4.
Operation of this switch causes
the fresh air door to close.
Water Valve
Test the water valve by momentarily disconnecting
the hose from the outlet (lower) side of the water
valve.
A slight spillage of water when the hose is removed
is normal. Excessive water flow indicates that the
valve is not closing properly. Remove the vacuum line
at the water valve and if excessive water flow con-
tinues then water valve is faulty. If the water flow
rate is acceptable with the vacuum line disconnected,
this indicates an improperly adjusted control cable or
faulty temperature thermostat. Adjust the control ca-
ble or replace the water valve or thermostatic valve
assembly as necessary, and retest.
Radiator Cap
It is an absolute necessity for the 1965 air-condi-
tioned vehicle to be equipped with a radiator cap hav-
ing a holding pressure of 15 to 16 psi, for hot weath-
er operation. If the radiator cap does not test within
these specifications, replace with a cap which does.
Condenser
Inspect the condenser fins for obstructions by for-
eign matter. Clean if necessary. Any obstructions to
the free flow of air across the condenser will decrease
heat dissipation from the condenser, decrease the ef-
ficiency of the condenser, and in turn, decrease the
evaporator's efficiency. These conditions result in in-
creasing the discharge pressure and horsepower load
on the engine. The use of a bug screen is not recom-
mended as it, too, will decrease the free flow of air.
Be sure the fan shroud is properly positioned. (If
so equipped.)
service port is depressed, opening the service port
valve.
The
Discharge Pressure Gauge
at the center of the
manifold is calibrated to register 0 to 300 psi. For all
tests this gauge is connected to the discharge service
port of the compressor. A service port adapter is used
to make this connection. The needle valve, located
below the discharge pressure gauge, is used to damp
out gauge needle oscillations so that accurate read-
ings can be obtained.
The
Compressor Inlet Gauge
is mounted at the
right side of the manifold. This mounting is for con-
venience only. There are no passages between this
gauge and the gauge manifold. The compressor inlet
gauge is calibrated to register 0 to 30" of vacuum and
0 to 150 psi. This gauge and the evaporator suction
gauge must be accurately calibrated so that the nee-
dles of both gauges are exactly at 0 before making
test. The compressor inlet gauge is connected to the
compressor inlet service port by a special service port
adapter.
This gauge is used, when checking the
EPR
Valve.
The
Center Manifold Outlet
provides the necessary
connection for a long service hose used when dis-
charging the system, using a vacuum pump to "pull a
vacuum'' before charging the system, and for con-
necting the supply of refrigerant when charging the
system. When performing the "Compressor Capacity
Test," TEST 7, the hose is removed and a special
test
cap is installed in its place.
The
Manifold Gauge Valves
should be closed when
connecting the gauge set manifold to the service
ports of the compressor. The suction gauge valve at
the left is opened to provide a passage between the
suction gauge and the center manifold outlet. The dis-
charge gauge valve at the right is opened to provide
THE GAUGE SET MANIFOLD
INSTALLATION AND TESTS
The Gauge Set Manifold is an indispensable
test
and diagnosis instrument. The Gauge Set Manifold,
Tool C-3740, has two compound suction gauges and
one discharge pressure gauge. Two accurately cali-
brated suction pressure gauges are required for the
evaporator pressure regulator valve test. (Refer to
Fig. 14).
The
Evaporator Suction Gauge
at the left side of
the manifold is calibrated to register
0
to 30 inches of
vacuum and
0
to 150 psi. This gauge
is connected to
the suction service port of the compressor. A special
service port adapter, supplied with the gauge set, pro-
vides the means of connecting the gauge set manifold
hose to the service port. When the adapter is installed
at the port and tightened, the stem of the valve in the
Fig. 15-Purge
Gauge Hoses
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