Chevrolet Light Duty Truck 1973 Service Manual page 88

1A-62 HEATER A N D AIR C O N D IT IO N IN G
BLOWER MOTOR RELAY
The blower motor relay is located on the blower side of
the blower-evaporator case (fig. 66).
Replacement
1. Disconnect the wiring harness at the relay.
2. Remove the relay to case attaching screws and
remove the relay.
3. Place the new relay in position and drive the
mounting screws.
4. Connect the relay wiring harness.
THERMOSTATIC SWITCH
The thermostatic switch is mounted to the blower side of
the blower-evaporator case. The switch sensing capillary
extends into the evaporator core.
Replacement
1. Disconnect the battery ground strap.
2. Disconnect the wiring harness at the switch.
3. Remove the switch to case screws and remove the
switch carefully so as not to damage the capillary
tube.
NOTE: Note capillary tube position in the
core so that the capillary may be reinstalled
in the same position (fig. 67).
4. Place the new switch in position, installing the
capillary in the core in the same m anner as at
switch removal.
5. Drive the switch mounting screws, connect the
wiring harness and the battery ground strap.
DISCHARGE PRESSURE SWITCH
The discharge pressure switch is located in the condenser
to evaporator line (fig. 68).
Replacement
1. Disconnect the battery ground cable.
2. Purge the system of refrigerant.
3. Disconnect the wiring harness at the switch.
4. Remove the switch from the refrigerant line.
LIGHT DUTY TRUCK SERVICE MANUAL