a/c blower performace observations (long)

["Walter" <Whalt@xxxx>]

If your a/c vents aren't putting out the amount of air you think they should
be, then I might have the solution to your problem.

If your OEM blower motor assembly (motor AND squirrel cage fan) has been
replaced with one that spins in the wrong direction, then this configuration
cannot be made to blow the proper amount of air from your a/c vents even
with the polarity reversed. You may get a moderate amount of air output,
but not the full amount. Here's why:

In addition to there being two types of blower motors (one type turns
clock-wise, the other turns counter clock-wise) there are also two types of
squirrel cage fans that attach to these motors (one is made to turn CW and
the other made to turn CCW).

To make a very long story short, make sure that your blower motor is
spinning CCW and that you have attached to it a squirrel cage fan that is
also designed to turn in the CCW direction.

If you want the very long story, then keep reading:

To make sure we are all on the same page, I'll list some definitions so that
you
will know what I'm talking about.

When I say clock-wise (CW) or counter clock-wise (CCW), I am talking about
looking into the open end of the squirrel cage fan. As applied to the fan
motor, I'm talking about looking at the end of the motor where the squirrel
cage fan attaches.

If you look closely inside the squirrel cage next to the center nut, there
is a direction arrow. On Deloreans, this arrow should point CCW and the
motor should spin CCW.

If these conditions are not met, then here are some possible explanations:

1) Your OEM motor was replaced with one that spins in the wrong direction
and you still have your OEM squirrel cage. There are two outcomes:
a) with negative ground, the assembly will circulate a moderate amount
of air in the CW direction and no useable amount of air will come through
the vents.
b) with the polarity reversed, the assembly will circulate a lot of air
in the CCW direction and a lot of air will come through your vents. All
should be well with the world, but your blower motor will have a positive
ground which isn't really safe.

2) Both your OEM motor AND your OEM squirrel cage were replaced with an
assembly that spins in the wrong direction. Now you are screwed! There are
two outcomes:
a) with negative ground, the assembly will move a lot of air in the CW
(the wrong) direction and almost no air will come through your vents.
b) with reversed polarity, the assembly will circulate a moderate amount
of air in the CCW direction and a moderate amount of air will circulate
through the vents, but not near as much as it should. From what I have read
in some of the DML back issues, it is very possible that some of you have
this situation and don't know it.

If you look inside your squirrel cage fan and cannot see a direction arrow,
then hold one hand on the outside of the squirrel cage and turn the cage
with the other hand. When turning in a CCW direction, the blades should cut
into your hand. When turning in a CW direction, the blades should wipe past
your hand. If you get the opposite, then you have the wrong configuration
for a Delorean.

If this information is repeated elsewhere in the DML, then I apologize for
posting it again. I tried searching the back issues, but couldn't find
anything about it, so I had to figure all this stuff out for myself the hard
way.

Walt Tampa, FL