--- Robert Weldon <rweldon@xxxxxxxxx> wrote:
> I have decided to tackle the non-functioning a/c
> system in my 72. As you all likely know, this is an
> Auto Temp II system. Anyway, the symptoms are:
> nothing happens when any of the buttons are pressed.
> I have gone through the shop manual and tried a few
> things. What I have determined so far is the little
> diaphram things on the air box do move when the
> buttons are pressed, however the fan does not come
> on, and I am not sure if the A/C compressor is
> functioning or not. There is no noises or any signs
> of activity I can determine anywhere in the system.
The compressor and fan are controlled by two vacuum
switches located under the dashboard on the passenger
side. The compressor switch is yellow. The fan switch
is green. Both have color coordinated vacuum lines and
electrical connections that must be firmly in place.
If the vacuum in the system is too low, neither switch
can work. Low vacuum can have a variety of causes, but
the most common are disconnected, pinched, or cracked
vacuum lines.
If the vacuum is good, the switches can be heard to
"click" when Hi-Def is pressed.
It is easy to see if the compressor is turning on.
Just turn on the car then hit Hi-Def and look under
the hood to see if the A/C compressor clutch is
turning. If not, the problem could be low vacuum to
the compressor switch, low pressure in the A/C system,
a disconnect in the wire to the A/C clutch, or even a
blown fuse.
> Anyway, the one thing that has me scratching my head
> is this. Checking the vacuum line connector at the
> buttons, as I thought I heard a vacuum leak (was
> something else not related to the a/c), there is a
> seven line coupling, the shop manual shows number 5
> is a "bleed wire". On my car, this vacuum line has
> a grey coloured piece of electrical wire stuck into
> the line, and the other end was not connected to
> anything. It ran towards the passenger side of the
> car, but I could not find where this wire may have
> went. Now, for the life of me, I cannot figure out
> what an electrical wire is doing stuck in a vacuum
> line hose, however the labeling as a bleed wire
> tells me this is supposed to do something, and the
> wire is in there quite tight, so maybe it belongs
> there?
The bleed wire belongs there and connects to nothing.
It seems to be a kind of plug.
> So, can anyone familiar with this vintage
> vehicle straighten me out on this "bleed wire"
> thing, and point me in the right direction on
> trouble shooting my a/c system. I am seriously
> considering stripping off a non autotemp system from
> a similar vintage Chrysler and converting, but
> thought I would take a shot at fixing this one
> first.
A noble task!
> I am aware that the main problem with these systems
> is that big plastic box on the passenger side fender
> liner, but how do I find out if this is good or not?
Examine the lower half of the servo for cracks and
signs of leakage. When you turn on the AutoTemp,
listen for the motor inside the servo; you should hear
it whir smoothly.
The servo controls fan speed and temperature. When it
sticks, the system will turn on, but be locked on one
temperature and one fan speed. Sometimes the servo can
be heard to labor, and the electrical drain is
noticable in the alternator gauge.
Since your car isn't running the fan or compressor,
your problem is probably not the servo.
> I couldn't find any screws, and the top seems to be
> attached by some pliable rubber or silicon plugs, so
> I am leery of pulling it apart, at least until I
> have secured a few spares to swap on.
Underneath those dabs of sealer are four screws that
hold on the servo lid.
> Anyway, I await the feedback from the sages here.
Hope this helps.
Dave Duricy
1968 Imperial Crown convertible
1973 Imperial LeBaron
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