Mike,
I confused the central flap motor and the temperature flap motor. You
have an easy access to the last one as described in the posts from other
listers. First remove the servo and check if the linkage moves without
the motor. Before rebuilding the motor, you want to be sure the linkage
or flap is not jammed. If the linkage moves with the motor removed, it's
time to rebuild the motor.
- Find a 5 or 6V DC power supply (any adaptor with 5 or 6V will do - do
not use 12V on these motor, they are rated for 7.2V or so and will burn
with 12V), a sandy eraser like the pink one at the end of pencil, a
cutter, some white grease and a dremel.
- First, remove the cover of the motor assembly: a few screws and 4
snaps if I remember well. Remove the cover slowly over a clean area as
one of the internal gears has its pivot on the cover. The gears are
greased and will catch any particles it will fall on, and you don't want
that.
- Then, disconnect and remove the electrical motor.
- Remove the brushes and springs on the motor. Once again, work over a
clean area as the springs have a strong tendency to fly around.
- Clean the contact surface of the brush with the eraser. The surface
should be a shiny orange gold once cleaned.
- Cut the pink eraser in the same shape as a brush but longer. Insert
the eraser where the brush usually goes. Make sure the eraser slide
easily in the brush holder. You want to be able to remove it at the end!
- Place the axle of the motor in the dremel and turn the rotor at the
lowest speed while gently pressing on the eraser. A few seconds should
be enough to clean the commutator. Do not "clean" too much as the
commutator have a very thin layer of metal.
- Blow on the commutator to remove eraser particles.
- Reinstall brushes and springs
- Put a very little drop of white grease on each bushing and remove the
excess with a paper towel or any other absorbing material. You'd better
not to use the white grease on the plastic gears in the motor assembly.
Some plastic gear materials require special silicone grease. I don't
know for the gear used in the HVAC motors but you'd better not take a
chance.
- Apply 5-6v on the motor to make sure it works flawlessly with only
small sparks. If the sparks are bigger than 1-2 mm, check the commutator
and brushes for trapped particles. If the motor miss, check for
particles in the motor cage.
- Reinstall the motor in the assembly, reinstall the cover with the gear
and that's it.
I have rebuilt the first HVAC motor more than 18 mo. ago and it's still
working perfectly.