type 44->a6/100 CC update info(long, but worth it!)

[Brett Dikeman <brett@pdikeman.ne.mediaone.net>]

After reviewing a A6/100 manual graciously donated for the weekend by 
Peter, I've found that the A6/100 climate control system and the type 44 
system are nearly identical.

Major differences:

-more "ut oh" sensors.  Example: The newer unit has a speed sensor for the 
compressor that compares compressor and engine RPMs; if too much slip is 
detected, the clutch is turned off.  However, certain compressors(mainly, a 
newer Nippodenso unit) don't have it, and those correspond to mid-1996 
model cars(the newer 1996 models do -not- have the switch, and hence have a 
"K" suffix/prefix on the part #.)
-more fan speed control(I think the type 44 has 4 levels; really low , low, 
medium, high), and possibly a different resistor pack for achieving the 
higher number of levels.  If they are different, fixable by swapping 
resistor packs(duh :)  However, the resistor pack looks identical to the 
one in the type 44 cars from the Bently drawings.
-mirror/window defroster switch integrated into CC head instead of seperate 
switch?
-additional sensor in the headliner.  Hey, don't 200q02v's have that too? 
I don't think they do, but there's a nice space for it, at least :)
-the radiator fan speed is more intelligently controlled.  If the A/C 
refridgerant hits a certain level, THEN the fan is switched on to "stage 
2"(on a type 44, this would be translated to switch on the fan at -all-.)
-coolant temperature sender is not in the block, but in a T fitting off 
some coolant hose.  2 options:they may have identical "responses" and we 
can continue to use the in-block sensor; if not, we just unplug it and 
install the a6 coolant sensor into some coolant line of our choosing.

-Vacuum system is different, but against what some listers said months ago, 
the a6/100 system is NOT completely electrically -ACTUATED-.  It is 
electrically -CONTROLLED-(as is the type 44.)

The a6/100 cars are more complicated, and that complication doesn't have to 
come along with the conversion so to speak.  Each flap(the flaps are in the 
same configuration as type44's) is controlled by a vacuum actuator.  Each 
actuator is controlled by a "2-way" vacuum solenoid, which is then fed off 
the main vac. res.

So what's the big difference?  Well, type 44's have all the solenoids in 
one, neat, nice, tidy box, not spread around the whole car.  Instead of one 
connector going from CC controller to the vacuum solenoid box, there's a 
connector that ties into a harness that goes off to various solenoids 
surrounding the heater core.  We'd actually be chopping a lot of wire off 
the harness if we installed a new unit into an older car.

The rhe a6/100's and type44 cars have -EXACTLY- the same method of control. 
I had feared the worst possible scenario, which was electrical-servo(RC car 
style) flap controllers, which would have meant disaster for the conversion.

Now, as far as I can see, the only barriers are things like, um, fitting 
the CC control/panel into the type44.  I -THINK- that the height of the a6 
head, minus bezel, is the same as the type44 WITH bezel.  It's gonna be a 
tight fit; that a6 unit just -might- be too tall to fit in.

Oops...I just read some more.  Looks like the "defroster" and "temp control 
flap" -might- be "servo" controlled; they are both directly controlled by 
electric motors.  The exact control method is very important.  Ex:if the 
motor is fed current all the time to keep it in one position, then that 
works well with our vacuum controlled flaps.  If it's fed positive, then 
switched off(assuming it stays in position), that's bad, but still 
workable.  If both flaps are servo(ie, motor w/feedback) controlled, that's 
-really- bad, unless the a6 flap controller can be placed into the type 44 
heater box.  The temp flap on the type 44 is also servo controlled, though 
it's by a motor -in- the vacuum servo box, if memory serves(or, this might 
be the heater core valve, I can't remember.)

Other than what I've briefly outlined here, the CC system components are 
nearly, if exactly, the same in a great deal of cases.

Last but not least, I need dimensions on both the type 44 unit and the 
a6/100 unit.  NOTE: I mean the dimensions of the UNIT, not the bezel.  The 
a6/100 bezel will definately have to be thrown away/not used.

So, if any of you have the time this weekend, yank off the bezel on your 
unit, and measure, with a pair of calipers or very good ruler:
-width of the unit
-height
----AT THE WIDEST/TALLEST POINT---

and we also need to know the size of the type 44 opening.  For now, I'm 
going to assume that the units have about the same depth.

Comments, especially from those who have worked on the CC systems on 
5k/pre-91 100/200's and also people who have worked on the a6/newer 100 CC 
systems.  I'd like to gather a few people who would serve as consultants on 
this, as, alas, I only have a 200q20v with an intact(in place) 
dashboard(and it's gonna stay that way until we're 100% sure we've got it :)

Brett
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Brett Dikeman
brett@pdikeman.ne.mediaone.net
~)-|
"Diplomacy is the art of telling someone to go to hell and making them 
happy to be on their way." - Mark Twain

"Oh no.  Not again." - The bowl of Petunias

"... it is important to realize that any lock can be picked with a big 
enough hammer." -- Sun System & Network Admin manual

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