Chevrolet 1977 light duty truck, Service Manual

Page: 91 / 861

1. Install the wire screen to the fro n t o f the core
and insert the plastic pins.
2. Install the expansion valve inlet and outlet lines
using new " O " rings coated with clean refrigeration oil.
Install the sensing bulb to the ev a p o ra to r outlet line as
shown in Figure IB-50; m ake sure the bulb has good
contact with the line.
N O T E : Add 3 oz. clean refrigeration oil when
installing a new core.
3. Install the upp er case an d supports to the core.
4. Install the lower core case and blower assembly.
5. Install the blow er-evaporator assembly to the
ro o f an d install the support to ro o f rail screws.
6. C onnect the re frig eran t lines to the blower-
e v a p o ra to r unit using new " O " rings coated with clean
re frig e ratio n oil.
7. C onnect the blower lead an d g round wires.
8. Install the re a r duct as outlined previously.
9. C onnect the battery g ro u n d cable.
10. Evacuate, charge and check the system.
BLOWER M O T O R S W IT C H
T h e three-speed (L O -M E D -H I) blower motor switch
is located in the instrum ent panel, just to the left o f the
ash tray (fig. IB-50).
Replacem ent
1. Disconnect the battery g ro u n d cable.
2. Remove the switch re tain in g screws.
3. Disconnect the w iring harness at the switch and
remove the switch.
4. To install, reverse Steps 1-3 above.
FUSE
T h e F o u r Season portion o f this system is protected
by a 25 a m p fuse in the junction block.
T he rear blower high speed circuit is protected by a
20 am p in-line fuse, located between the ju n ctio n block
and the rear blower motor switch.
C60 SYSTEM-G MODELS
C O NDENSER
Replacement (Fig. IB -5 2 )
1. Remove the batery g round cable and com pres­
sor clutch connector.
2. Purge the system o f refrigerant.
3. Remove the left and right hand h ead lam p
bezels and park in g lam p lens. Place a piece o f protective
tape over upper surface o f the front b um per. Remove
the grille to ra d ia to r support screws and remove the
grille.
4. Remove the screws from ra d ia to r center brace
and remove the bracke.
5. Remove the u pper ra tia to r supports. Move the
u pp er edge o f the ra d ia to r rearw ard to gain access to
condenser attachment.
6. Remove the condenser to ra d ia to r support nuts
and bolts.
7. Disconnect the condenser inlet and outlet lines
and remove the condenser. C ap or plug the open
connections at once.
8. Remove the condenser m ounting brackets from
the condenser.
9. To install, reverse Steps 1-8 above. Add 1 fluid
ounce o f clean refrig eratio n oil to a new condenser.
C A U T IO N :
Use new "O " rings, coated with
clean regrigeration oil, when connecting all
refrigerant lines.
10. Evacuate, charge and check the system.
R ECEIVER-DEHYD RATO R
Replacement (Fig. IB -5 2 )