Re: 84 5K Avant climate out of control

[ti@amb.org (Ti Kan)]

J4KQ4me@aol.com writes:
>   Any insight into why my 84 5K avant's climate control blower only operates
> on defrost? For other reasons, (Or should I say the usual reasons) I've
> replaced the blower motor, the head unit and the programmer. The blower will
> always come on in Defrost, but will only occasionally operate in any other
> mode.

Check the blower motor thermoswitch.  This switch will inhibit blower
operation until the engine reaches a certain temperature so that you
don't get a blast of cold air on your face.  The defrost mode overrides
this switch so that's why it works.

The switch is located at cylinder #1 on non-turbo 5000 models.  On
turbo 5000s, it's on a T-fitting in the coolant pipe just below the
control pressure regulator.

You can pull off the two electrical connections and measure the continuity
of the switch when the engine is warm.  It should be closed.  Also, you
can check the wiring by shorting the two connectors to each other.  This
should cause your blower to work in all modes.  If the switch is okay and
shorting the wires still doesn't make the blower work, then the problem
is something else.

-Ti
96 A4 2.8 quattro
84 5000S 2.1 turbo
80 4000 2.0
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