now - even on the coldest setting it always seemed to be blowing air warmer
than ambient (assuming I wasn't using aircon). This is not a good thing in
Summer. So, a couple of days ago I made the effort to investigate, took
about 5 minutes of actual effort (once I found the right things) and now get
comparatively cool air blowing.
The tradeoff is that the hot setting might not be as hot as before - I'm not sure
about that yet. Maybe in Winter I will spend another 5 minutes of my
precious time & set things back for hottest possible air.
The problem was with the flapper door which controls hot/cold. When it is
adjusted to factory spec you get full hot but not full cold - the range of travel
of the slider on the dash is not as great as the range of travel of the door
mechanism. Factory adjustment is to set things up for the hot end of the
travel. It is very easy to fix - the only tool required is a phillips screwdriver to
undo the plastic panel underneath the steering column (even that might not
be necessary, but it lets more light in to where you're working).
Sitting on top of the transmission tunnel (just to the left of the drivers feet) is
a plastic box with a vaguely triangular shaped air outlet facing sideways at
the bottom, and a control cable (somewhat like a bicycle brake cable -
they're called Bowden cables) attached to some levers on the side. The
sheath of the cable is clamped by a clip on the side of the box.
The end of the cable is just a loop slipped over a bit that sticks out of the
lever - pull it off with your fingers. Pushing the lever towards the front (of the
car) makes things hot, toward the back makes things cold - right at the cold
end of the movement there is a snap action where it goes 'clunk'.
Pull the cable sheath out of the clip (pulling toward the drivers door), set the
dash control one click from coldest, re-attach the cable to the lever, set the
lever to coldest position (clunk!) and snap the cable sheath back into place.
That's the adjustment complete. Screw the plastic cover back on under the
steering column. Finished.
If you want pictures, have a look at www.miata.net in the Garage-Interior
section - there is an article called "99 Heater Problems - Too much heat".
The direct URL is http://www.miata.net/garage/heater_cable.html
The pictures are mostly applicable (click on them for larger versions). The
only real difference in the article is that you take off the steering column cover
instead of taking out the glovebox to gain access.
I'm off for a month-long driving holiday shortly - having cool air on my feet
while cruising with the top down is going to be great
Karl.
