Blower Motor Assemblies; Rear Duct - Chevrolet 10 1971 Series Chassis Service Manual

Fig. 48— Thermostatic Switch, Blower Motor Relay and
Blower Motor Resistor Locations
4. Install the knob onto the switch shaft.
5. Connect the battery ground cable.
INTERMEDIATE DUCT (Fig. 46)
Replacement
1. Disconnect the battery ground cable.
2. Remove the dome lamp lens and bulb.
3. Remove the sealing strips at each end of the duct.
4. Squeeze the sides of the duct together and remove the
duct from its retaining flanges.
5. Remove the dome lamp screws and remove the duct
from the vehicle.
6. To install, reverse "Removal" Steps 1-5, being
careful not to damage the retaining flanges when
reinstalling the duct.
REAR DUCT (Fig. 46)
This duct covers the blower-evaporator assembly and
connects to the intermediate duct.
Replacement
1. Remove the sealing strip at the forward edge of the
duct.
2. Remove the roof panel trim strip.
3. Remove the five screws securing the rear duct.
4. Remove the duct from the retaining flanges at the
rear, side and front retainers (in that order).
5. Pry the ferrules out of the drain tubes and disconnect
the drain tubes from the rear duct.
6. Remove the duct assembly.
7. To install, reverse "Removal" Steps 1-6.
THERMOSTATIC SWITCH, BLOWER M OTOR RELAY
A N D /O R BLOWER M OTOR RESISTOR
These components are attachedto the blower-evaporator
upper shroud as shown in Figure 48. The rear duct must
be removed to gain access to these components.
Replacement
1. Disconnect the battery ground cable.
2. Remove the rear duct as outlined previously.
HEATER AND AIR CONDITIONING 1A-35
It is not necessary to disconnect the
NOTE:
drain tubes to gain access to these parts.
3. Relay — Disconnect the wiring harness, remove the
two mounting screws and remove the relay.
Resistor — Remove the two mounting screws, lower
and disconnect the harness connector; remove the
resistor.
Thermostatic Switch — Remove the two mounting
screws. Remove the sensing capillary from the
plastic clips, disconnect the wiring
remove the switch.
4. To install, reverse "Removal" Steps 1-3.
When installing the thermostatic switch,
NOTE:
be sure to replace the capillary in the plastic
clips (Fig. 49).

BLOWER MOTOR ASSEMBLIES

Removal
1. Disconnect the battery ground cable.
2. Remove the rear duct as outlined previously.
3. Remove the blower motor ground straps at the
center connector between the motors.
4. Disconnect the blower motor lead wires.
5. Remove the lower to upper blower-evaporator case
screws and lower the lower case and motor assem­
blies.
Before removing the case screws,
CAUTION:
support the lower case to prevent damage to the
case or motor assemblies.
6. Remove the motor retaining strap and remove the
motor and wheels.
motor shaft.
Installation
1. Place the blower wheels onto the motor shaft and
install the set screws; do not tighten the set screws
at this time.
Be sure that the blower wheels are
CAUTION:
installed as shown in Figure 50.
2. Install the blower motor retaining strap and foam.
T H E R M O S T A T IC S W IT C H
A IR S E N S I N G
^ / C A P ILLA R Y
" . ........ .... . ... ... 7
Fig. 4 9 — Thermostatic Switch C apillary Installation
harness and
Remove the wheels from the
pLAST|C
CLIPS
E V A P O R A T O R
C O R E
10-30 CHEVROLET TRUCK SERVICE MANUAL