HVAC push button control repair (was: Vacuum Hoses Connect to Plastic Nipples) VERY long read!

["Dick Benjamin" <dickb@xxxxxxxxx>]

Here is the text of a message I sent out recently regarding replacing the
push button vacuum control used on the non- ATC cars.   It also covers the
blower switch on the non-ATC cars.

Your 1968 may have ATC, and if so, this may not pertain directly to your
car.  However, if the push button control is fully operational on an ATC
car, but the vacuum fittings are broken off the back, one can buy one of the
controls described here and switch the rear plastic part with the ATC
version - you have to do a little drilling and taping to hold it together
(it must be vacuum tight), but I have done this with good success on two ATC
cars so far.  If you are not comfortable with this operation (and I use the
term deliberately), you can watch ebaY for one of the ATC controls to run,
or you can beat the bushes for one from one of the new parts vendors (Frank
Mitchell or Brad's NOS - I think you can find one for around $50 that way.
Alternately, you can buy the switch mentioned in the second response below,
take it apart and put the electrical program device from your old one into
it.  Either way, you have to deal with resealing the plastic parts.

I've read the other's suggestions about repairing the broken off nipples.
You can try those first.  I don't think I would be able to pull those
repairs off myself - there are 7 nipples within a space of 3/8" by 3/4"
inch, each is very brittle with age, and they must all be vacuum tight, and
strong enough to withstand the vacuum harness hanging off them while the car
jounces around.  I am a big booster of JB Weld too, but I think this is
asking too much of it.

The old text is in two pieces - please read them both:

1.


I thought some might be interested in some repair work I have just completed
on the AC system in my 67 Convertible, with standard (non-ATC) air
conditioning.     I have the complete dashboard out of the car, and am going
through every switch and control device, rebuilding or replacing as
necessary to bring the car back to as new operation of everything.I
decided
> to search for replacement new controls for both the fan 4-speed switch
> ("Low", "Medium", "High" and "WOW!") and the push button vacuum routing
> switch that controls the mode of the system ("OFF",  "MAX AC", "AC",
"HEAT"
> and "DEF").
>
> The reason I decided to replace these controls is that the push button
> assembly had developed some vacuum seepage, making the response of the air
> control flaps very sluggish, plus the push buttons were hard to push
unless
> one pulled the previously depressed button out before making another
> selection.  The blower switch had become very touchy on the "WOW"
setting -
> one had to very carefully position the switch lever to make it stay on
that
> setting - it tended to slip off to the "HIGH" setting, hardly a serious
> problem, but an irritation to the perfectionist (does anyone hear my
call?).
> I took the switch apart to diagnose the problem, and decided it was caused
> by warpage of the phenolic substrate in which the terminals are staked.  I
> made the repair, but I didn't feel it was a permanent cure, as the board
can
> just warp further. It is such a royal pain in the posterior to get that
> switch out of the dash that I decided I wanted to replace it with a new
one
> of better design.
>
> I tried to find these controls on ebaY, PartsVoice etc., without success.
> Then I tried NAPA, - same story.  I took the "buyer's guide" from NAPA and
> began comparing shapes and functions, and found substitutes that others
may
> be interested in making a note of, in case you ever have the need.
>
> For the push button control, Mopar number 2587 564, you can directly
> substitute a Mopar number 3431 020K, which was used on 69 - up non ATC
cars
> from lesser Mopars, for instance my 69 Newport.  The only difference is
the
> presence of an extra electrical terminal on the blower feed lugs on the
> right rear of the switch.  This switch has three terminals, while the
> original only had two. To use it, just ignore the extra terminal, which is
> the one toward the center of the control unit.   NAPA stocks this control
> under their number ECH-HC-205.  AutoZone also stocks it, but you have to
ask
> for a 1969 Chrysler Newport switch.  As I recall, their number is WF259,
but
> double check that as it is from memory.
>
> For the blower speed control, Mopar number 2587 321, you can substitute a
> Mopar number 4261 306, which was in use at least up to 1980 in the Dodge
> trucks.  The NAPA number for this is ECH-HC-202.  You cannot use it
> directly, you have to change the  wire connections to the back of the
> switch.   Directions to do this are as follows:
>
> 1.  Note the 4 #16 wires to the back of the old switch.  They are Brown,
> Light Green, Dark Green and Tan (on some cars the light green wire looks
> white, according to my color consultant (I'm color blind, so I take her
word
> for it).
>
> 2.  Note that the pattern of the connection lugs on the back of the new
> switch is in the shape of the letter "A", with one terminal at the right
> bottom of the "A" - this one gets the brown wire.  The center bar of the
"A"
> gets the light green wire.  The apex of the "A" gets the dark green wire.
> The left bottom of the "A" gets the tan wire.  Clip each of these wires
off
> the old switch, strip back 1/4 inch of insulation, and crimp on a new
spade
> lug female to each wire. Then solder the crimp so that it won't work
loose,
> overheat, and ruin the new switch.  Then, using heat shrink tubing, put an
> insulating sleeve over each crimp lug, so that they cannot contact each
> other when installed on the switch, as the terminals are VERY close
> together. Do all this work with the wires unplugged from the switch, to
> avoid overheating it.
>
> 3. Now, you have to remove the electrical operating doo-dads from the new
> switch and install them on the old switch, as the handles and mounting
> bracket are different.  Carefully unbend the 3 bent over tabs holding the
> back of each switch to its housing, and transfer all the contents of the
new
> switch to the old one.  You will have to slightly extend the notch for one
> end tab to make it fit the old switch housing, but you can do this with a
> nail file (if your wife isn't looking).  Be sure to transfer the inner
> slider and spring assembly also, as they are slightly different and the
old
> one won't work on the new terminal board.   Install the new parts in the
old
> housing, carefully bend the holding tabs back down, and Bob's your uncle!
> Plug in the wires as described above and you have a complete new control
> system for the AC and Heater/Defroster system.  How sweet it is!
>
> Any questions or difficulty, feel free to ask me.
>


And the second quote:

2.(responding to someone who asked if the above applied to an ATC car)

> Dick, does any of this apply to 68's?  i.e., can these substitute switches
be
> used on the 68's?

As far as I know,most 68s have ATC, so the answer would be no.   For the few
68s with standard AC, the same parts would likely be
used, but I've never seen one with standard AC so I can't be sure.

There is a close equivalent to the ATC type push button unit, the NAPA
HC6401, but as I recall, I had to take it apart and modify the electrical
portion of it's program.  The vacuum hose program was right, though, again
as I recall.  I'm using it on my gold 68, but that repair was about 15 years
ago and I
forget the details of what I did.

These are pretty obvious once you get them apart, but you have to melt or
grind off the plastic retaining devices, and then drill and tap out the
holes for new screws when you get them changed to the program you want.  If
yours still has all 7 vacuum fittings and the plastic housing is in good
shape (meaning no vacuum leaks), you can rebuild it - I've done that a
couple of times on other cars.  It is painstaking work, requiring good
light, good eyesight, some tiny tools, common sense and a steady hand - I'm
sure that anyone who has rebuilt a carburetor can handle this too.  You of
course need the FSM to tell you which vacuum hose should be active at each
push button position.  The ATC cars don't have a blower speed switch.

Dick Benjamin

----- Original Message -----
From: "Print Bear" <>
To: <mailing-list@xxxxxxxxxxxxxxxx>
Sent: Tuesday, April 01, 2003 3:44 PM
Subject: IML: Vacuum Hoses Connect to Plastic Nipples


> Thanks to Dave I managed to remove my 68's dash panel and revealed to
> me was the scourge of the ages:
>
> 1. Water damage to the Headlight Switch: I will attempt to disassemble
> and rejuvenate this
> 2. Water damage to Dashboard light dimmer: Same as above.
>
> These will involve drilling out the stamping and probably watching a
> bunch of springs leaping into my face never to be reassembled again. I
> will fill you in on this operation as it happens. Hoping that this will
> be the remedy for non-operative parking lights and dash lights.
>
> Next, I encountered the source of a strange  and erie sound that comes
> from the dash area when the car is running. I wasn't sure if it was the
> Speedo cable or the vacuum for the parking break. Instead, it is the
> vacuum switch which controls the rear window defogger or the rear seat
> heat. The switch is white plastic and has several nipples, about 3/8"
> long, maybe 1/8" diameter, arranged on the rear of the body. They, in
> turn, fit into a female socket made of rubber. The problem: One of the
> nipples is inside the socket, broken off from the back of the switch,
> and at least one of the nipples, still on the switch, is cracked and
> about to come off. Air is being sucked into the cracked and broken
> nipples and that is making the sound I'm hearing.
>
> Is there a way to glue these back on and strengthen the cracked one?
> I'm sure there's no replacement for this part. I wouldn't even ask. It
> has a 58024 and a Pentastar stamped into the plastic.
>
> I have uploaded pictures of the operation: Two corroded switches and
> the back of the plastic vacuum switches to the following URL:
>
>   http://homepage.mac.com/printbear/PhotoAlbum4.html
>
>