Chevrolet 10 1971 Series Chassis Service Manual page 56

HEATER AND AIR CONDITIONING 1A-38
Fig. 54— A nti-D iese lin g Relay
G M CHEVROLET SYSTEM
COMPRESSOR, CONDENSER, RECEIVER-
DEHYDRATOR A N D SIGHT GLASS
Replacement of these components is covered under
"A LL SYSTEMS," Pages 1A-23 to 1A-27.
BLOWER RESISTOR
Replacement
1. Disconnect the battery ground cable.
2. Remove the glove box and door assemblies.
3. Disconnect the resistor wiring harness.
4. Remove the two resistor mounting screws and remove
the resistor as shown in Figure 55.
5. To install, reverse "Removal" Steps 1-4.
ANTI-DIESELING RELAY
This relay is mounted to the dash panel at the forward
side of the blower-evaporator unit (Fig. 55). Its purpose
is to actuate the compressor clutch when the ignition
switch is turned off.
Replacement
1. Disconnect the electrical connector at the relay.
2. Remove the relay to dash panel attaching screw and
remove the relay.
3. Place the new relay into position and drive the
mounting screw.
4. Connect the wiring harness.
BLOWER A N D /O R THERMOSTATIC SWITCHES
The blower and thermostatic switches are located inside
the duct assembly as shown in Figure 56. The coolant
system need not be opened up to gain access to these
switches. However, the entire unit must be lowered from
its dash mounting.
Fig. 55— Blower Motor Resistor
Removal
1. Disconnect the battery ground cable.
2. Remove the glove box and door assemblies.
3. Remove the four dash to duct attachments and the
bracket to kick pad screw.
4. Lower the entire unit and remove the duct to case
screws.
5. Remove the duct from the case being careful not to
damage the wiring harness or refrigerant lines.
6. Pull the switch knobs off the shafts.
7. Remove the duct rear cover screws and carefully
prying at the cover clips, with a small screw driver,
remove the duct cover.
8. Disconnect the electrical connections at the switch
being replaced. If the thermostatic switch is being
replaced, disconnect the capillary at the bracket in
front of the evaporator core.
9. Remove the switch mounting screws and remove the
switch.
Installation
1. Install the switch mounting screws.
THERMOSTATIC
SWITCH
TH
SWITCH CAPILLARY
Fig. 5 6 — Thermostatic and Blower Switch Locations
G REEN
I
D ARK BLUE
I / BLACK WITH
/ RED STRIPE
SWITCH
10-30 CHEVROLET TRUCK SERVICE MANUAL