Replacing Climate Control Diaphragms
The other niggling problem was with the climate control system. Don't
ask me why, but both diaphragms that control the fresh air/recirculate
flaps did not work. I verified with a hand vacuum pump that neither held
a vacuum. Besides the obvious vacuum leak, this leaves the flaps in the
fresh air mode all the time. It's like having a permanent Gardner Mod.
It wouldn't be a
problem in a more forgiving climate, but in the summer in Arizona, it's
tough enough keeping the car cool without having to continually cool
110+°F air. I tracked a couple used diaphragms down and waited for the
opportune time to install them. This seemed like it -- three weeks ago.
(Can you say shipwright's disease?)
Now, to know what part I'm talking about, put your head in the footwell
and look over by the outside kick panel. As you scan up the kick panel,
one of the first things you'll see is a gold-colored metal "can" with a
tiny blue the first things you'll see is a gold-colored metal "can" with
a tiny blue other side, too. As you can see, r&r is not going to be
Disclaimer: I probably removed more than I needed to, as I fumbled my
way through this project. I'll tell you what I removed, unless I later
discovered it was totally unnecessary.
I started on the passenger side, removing all the under-dash covers. The
glovebox is a good idea, too. I'm not sure it is necessary, but it does
make access much easier. Next, you have the fuse box and all the other
electronic gadgetry which is bolted to the front of the blower fan.
Remove the lower nuts, but just loosen the upper one. It slides down and
will hang by the wires. The fan and flap assembly is secured by one nut
and one bolt. The nut is way up between the kick plate and the blower
case. The bolt is pretty is way up between the kick plate and the blower
case. The bolt is pretty obvious on the opposite side. Disconnect the
wires from the inside side of the blower. Disconnect the pigtail (fan
motor wires) that comes through the blower case on the other side.
Disconnect the vacuum line to the diaphragm and the rubber air duct that
connects the fan output to the big box of flaps and coils and levers and
linkages behind the console. (I don't even want to
think about that!)
Believe it or not, the blower/flap unit is now free. That didn't sound
too hard, did it? As you wiggle it around, you won't believe me. It
seems free,but you just can't seem to get it out. You don't want to yank
too hard for fear of breaking something (and I eventually did), but it
just seems impossible to remove. That is what baffled me for two weeks.
There are two flaps in the unit. One at the bottom opens to recirculate
air. Unbeknownst to me there is another flap at the top. This one opens
into theplenum fed by the cowl vent. If you carefully (very carefully)
remove the cowl vent and drop down to look into the furthest recesses,
you can see it in there. (I have found that gentle prying with a
computer slot cover -- the little L-shaped metal piece that covers the
slots in the back of a computer -- prying evenly around the outside of
the chrome vent cover brings it up enough so that you can grasp the
edges and wiggle it free.) Anyway,the two flaps are linked by an
amazingly complex system of lever arms and rods, which are quite
ingenious when you see it work. When there is no vacuum, the bottom flap
is closed and the top is open. The top flap is round
on the ends and the cutout in the plenum is the same shape, so when the
flap is open it hangs up on the narrower part of the opening.
Here is the secret: You need to pull the bottom flap open with you hand.
This closes the top flap and aligns it with the hole in the plenum.
Sometimes it still takes a little fiddling, rocking, and rolling, but
the unit will eventually fall out.
If only I had known that before I had removed the crash rail, the
defroster/side vent ducts, the dash face, and many other nuts and bolts
that looked important. When all else failed, decided to use a little
light persuasion with a pry bar. I broke one of the flap lever arms. No
glue I had would adhere to it. I took the smallest drill bit I had, with
the intention of epoxying a small stiff wire inside the piece. I drilled
from the fracture out one end, then drilled in from that end through to
the other piece. Then I broke my drill bit off in the hole. It would
have been a move of pure genius if I had planned to do that, but even as
I cursed my misfortune I realized my good fortune. I just left the piece
of drill bit in there an am planning on buying many cheap drill bits for
similar repairs in the future.
Once you have the blower/flap unit out, replacing the diaphragm will be
obvious. Take the time to remove the squirrel cage from the flap unit
and blow it out with compressed air. I had half an inch of crud stuck to
the outside of the motor. If you have some chewed up weather-stripping
where the flaps close, you might as well replace it.
Everything goes back together the way it came apart. If you have a
vacuum pump, check the operation of the flaps. Make sure they hold their
position. When putting the blower/flap assembly back in, pull the bottom
flap down, get it positioned, and loosely put the nut and bolt in place
to hold it. Before you tighten things down, find all the wires and
vacuum lines and connect them. Manually work the bottom flap a couple
times to center the top flap in the cutout in the plenum. Once it is
moving freely, tighten it down.
The driver's side is the same except that the rubber duct between the
fan and the console box is a royal pain to get back on the fan. Working
above the steering column was nearly impossible, but I finally managed
to get it connected. I don't know if my duct was misshapen or what, but
then the other side just barely reached the tubes coming from the
central box. Trying to get those on we pulled the fan end off. This was
real test of patience.
With what I and you know now, I think you could cut the passenger side
r&r time down from 2-3 weeks to about 2-3 hours. Add about two hours to
the drivers side for that stupid duct.
I surely hope this helps other listers, I still have my entire dash to
put back together.