Chevrolet Light Duty Truck 1973 Service Manual page 93

Fig. 75-Blower Switch (C-K Overhead System)
using new "O " rings coated with clean refrigeration
oil. Install the sensing bulb to the evaporator outlet
line as shown in Figure 74; make sure the bulb has
good contact with the line.
NOTE: Add 3 oz. clean refrigeration oil
when installing a new core.
3. Install the upper case to the core.
4. Install the lower core case and blower assembly.
FLOOR M O UN TED SYSTEM -G MODELS
C O M P O N E N T PART REPLACEMENT
HEATER A ND AIR C O N D IT IO N IN G
5. Install the blower-evaporator to the roof panel
support.
6. Connect the refrigerant lines to the blower-
evaporator unit using new "O " rings coated with
clean refrigeration oil.
7. Connect the blower lead and ground wires.
8. Install the rear duct as outlined previously.
9. Connect the battery ground cable.
10. Evacuate, charge and check the system.
BLOWER MOTOR SWITCH
The three-speed (LO-MED-HI) blower motor switch is
located in the instrument panel, just to the left of the ash
tray (fig. 75).
Replacement
1. Disconnect the battery ground cable.
2. Remove the switch retaining screws.
3. Disconnect the wiring harness at the switch and
remove the switch.
4. To install, reverse Steps 1-3 above.
FUSE
The Four Season portion of this system is protected by a
25 amp fuse in the junction block.
The rear blower high speed circuit is protected by a 25
amp in-line fuse, located between the junction block and
the rear blower motor switch.
CONDENSER
Replacement (Fig. 76)
1. Remove the battery ground cable and compressor
clutch connector.
2. Purge the system of refrigerant.
3. Remove the screws that retain the headlight
mouldings and remove the screws for the grille.
Remove the mouldings then remove the grille.
4. Remove the screws from radiator center brace and
remove the brace.
5. Disconnect the condenser inlet and outlet lines and
cap or plug the open connections at once.
6. Disconnect the receiver-dehydrator outlet line and
cap or plug the open connections at once.
7. Remove the (4) condenser bracket bolts and remove
the condenser from the vehicle.
8. Remove the condenser mounting brackets from the
condenser.
1A-67
LIGHT DUTY TRUCK SERVICE MANUAL