'84 5kS Climate Control

[Michael Spiers <mikes@specnet.com>]

There are some problems with my (her, whatever) '84 5kS that I've never seen
addressed on here, so I'm a gonna ask 'em.  For one thing, the dash control
RARELY lights up (meaning, you start the car and there is no digital display.)
 The backlights for nighttime viewing will always work, but the digital part
only works every once in a while.  When the digital part is unlit, none of the
buttons work either (meaning, you push the buttons and the lights above the
buttons do not light up either.)  It's kinda like the thing isn't getting
power, but since the running lights come on, I don't think this is the problem.
 When the digital doesn't lite up, usually the blower motor comes on full blast
and cranks out whatever temperature air is in the engine compartment (cold in
winter, hot in summer) and always out the floor/defroster vents.  When the
digital is on, if you go fron like 65 to 90, the vents DO change from the
footwells/defroster to the dash vents, but the temperature air coming out
doesn't change from hot to cold.  It seems to me that in the winter time, if
you have the car set at 72, the heat should turn off, but all this thing does
is go from warm air at your feet to warm air in your face, which tells me the
heater valve isn't closing.  It WILL go from hot to warm, and the fan will slow
down when the car is starting to warm up and reach the correct temperature, but
for some reason when the correct temperature is attained the thing doesn't shut
the valve, it just starts spewing warm air out the dash vents.  The climate
control in this heap is the old style, so you can't run the "outside air
temp/off" deal to see what all works.  So, no digital is problem number one.
 Problem number two is that in the winter time, you get heat about half of the
time.  The digital dash seems to work relatively well in the winter time (if
you start the car and the digital doesn't come on, if you turn on the driving
lights the digital dash will usually come to life.)  The easy fix is to yank
the vaccuum hose out of the heater control valve so it stays open, but this
isn't the desired fix.  So, the heater valve is usually shut when the heat is
desired, and usually open when heat is not desired.  The A/C hasn't worked in
years either, although the heat stopped working about a year before the A/C
stopped working.  Right now, the digital hasn't come on in about three months,
and the blower motor is on high, blowing engine-compartment temperature air out
the defroster and foot ducts.  This was "fixed" by yanking the fuse for the
blower motor, but again this is not the desired fix.  So, is this a programmer
problem, a control unit problem, or just a sign that I should push the car off
the cliff just outside Golden?  Oh yeah, the rear defroster doesn't work
either.  I first suspected a blown relay, because the light and button on the
digital dash works just fine, but the defroster never came on.  A new relay
just turned the defroster on and never let it go off unless the ignition was
off, so now there is a switch from an '87 5kS in there to fix that problem.
 I'm assuming the control panel is shot as far as the rear defroster button is
concerned.  Anyone with any idea would be greatly appreciated, winter will be
here (in Colorado anyhow) before all too long and I want to have this problem
solved one way or the other so she doesn't have to drive around in a snowsuit
to keep from freezing to death in the thing...  Oh yeah, one more question.
 Anyone know if a later-style control panel/programmer can be retrofitted to
this thing relatively easily?  Most of the boneyards around here have an
over-abundance of later style stuff, but none of the old-style junk that the
'84 has.  Any ideas are GREATLY appreciated!

-- 
-Mike
87 5000CS TQ
84 5000S (2,000 miles away and a mile high)