In alt.home.repair on Sun, 22 May 2005 10:38:25 GMT "Joseph Meehan"
posted:

meirman wrote:
In alt.home.repair on Sat, 21 May 2005 22:37:09 GMT "Joseph Meehan"
posted:


Thanks for replying.

My '95 Chrysler heater/AC fan speed switch no longer works in
position 2,

That is the answer to your question. It is not the switch that
is bad, it is a resistor that is gone. They tend to fail one at a
time.

Thats what I thought at first, but

a) The switch tested bad in the second position only.

That would be the case if the resistors were integrated in the switch.

True, but they're not. They're under the dash, below the glove
compartement, with the resistors themselves in the air duct from the
outside. I think that is to help cool the resistors, which in my GM
cars were just wire coils suspended in air, with no non-conductor
surrounding them.

b) A friend gave me a control panel from a Chrysler Caravan truck that
he was scrapping**. The second fan speed, all the fan speeds work
fine with his control panel. (I can't just take the fan speed switch
from it because it won't fit in my heater control panel. And I can't
use his control panel because almost all the connections are different
in his control panel. The vacuum hoses are longer, not a problem;
the electrical connection might be in the same place; but the hot/cold
door control cable connects at the left rear corner instead of right
rear, and is meant to come in at a 90 degree different angle. I
tried to find some slack in the cable, but there isn't. (It's very
hard, almost too short, even to connect the cable to the control panel
it was designed for.)

The speed is controlled by the resistors, but if the switch is bad,
then no current will reach the intended place on the resistor pack.

Have you established that there is a separate resistor pack? (It is
often located in the cool air stream to help cool them)

LOL. I just said that!

Assuming it is the switch, I would suggest replacing it rather then
trying to fix it. I have never need a car switch that was going to be easy
to fix.
Be sure to use a the special grease made to electrical contacts if you
decide that is needed.



Meirman
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