Blend Door Motor - Hummer H1 Service Manual

11-42 Heating/Ventilation/Air Conditioning (HVAC)

BLEND DOOR MOTOR

Replacement
1. Disconnect motor electrical connection.
2. Remove 3 nuts securing motor to bracket (Figure 11-68).
SPACER
7-P11-002
Figure 11-68: Temperature Blend Door Motor
NOTE: Do not loosen set screw on door shaft adapter!
3. Remove motor by pulling it straight off. Do not discard the
spacers behind the motor.
Installation
Reverse above removal procedure for installation.
Heater Core Replacement
NOTE: Screws should be noted for length as they are removed
to aid in correct reassembly. Some screw lengths are critical to
prevent interference with interior parts.
NOTE: Most of the screws used are threaded into the plastic
housing of the HVAC unit. Care should be used to prevent
over-tightening of the hardware and stripping holes out.
1. Remove the unit from vehicle (Refer to unit removal pro-
cedure this section)
2. Set the HVAC unit on a bench so the copper heater tubes
are visible and upwards.
3. Remove permagum tape from heater tubes at passthrough
plate and discard.
NOTE: Foam tape and permagum tape should always be re-
placed with new material where it was removed from during
disassembly. The tapes are used to insulate hot and cold parts
and prevent condensation from dripping on the passenger
floor.
4. Remove 4 bolts securing heater tube mounts to
passthrough plate (Figure 11-69).
MOUNTING PLATE
DOOR SHAFT ADAPTER
TEMPERATURE BLEND
DOOR MOTOR
NUT
Removal
ORG
7-S11-032
Figure 11-69: Heater Core Tube Removal
5. Cut sealer around heater core retaining plates (Figure 11-70).
6. Remove 2 retaining plates (Figure 11-70).
HEATER CORE
RETAINING PLATES
SEALER
Figure 11-70: Retaining Bracket Removal
7. Pry heater tube mounting plate away from passthrough
plate. Pry only in the middle to prevent damaging seal
surfaces. Heater tubes extend past the mounting plate and
into the passthrough plate (Figure 11-71).
Figure 11-71: Removing Heater Core
8. Pull lightly on heater core to keep heater tubes parallel
with the HVAC case. Do not allow the mounting plate end
to come away faster than the core. Note positioning of any
foam tape on the heater core, and duplicate on new part.
9. Discard the sealing washers on the heater tubes and repair
or replace heater core as necessary.
Reverse removal for installation.
NOTE: Observe screws as they are removed to ensure corrects
screws are used in the correct location on assembly.
______________________
HEATER CORE
EXTENSION TUBES
®
7-S11-034
7-S11-035