climate control hacking

[Eliot Lim <eliot@lanmola.engr.washington.edu>]

greetings.

lately i have been goofing around with the delco climate control panel's
debug mode.  interesting discoveries.

background:

to get into debug mode, press "outside temperature" and "off"
channel 7 is the most interesting.  to get there, hit "warmer" 7 times.
the display indicates the state of the system.. i.e. which vents are
open, electric fan running, a/c compressor engaged etc etc.


recirculate:

i have not been able to get the system to recirculate with a/c on.
this is nice to have if the car in front of you is belching oil or
diesel fumes.  setting "LO" temperature is supposed to do it, but
according to the display it doesn't.  only recourse is "OFF"


a/c:

i have not tried the a/c in cold weather, but in temperatures over
70F, the compressor and the electric fan runs continuously.
temperature regulation is achieved by (gasp!!) opening the heater
valve.  no doubt the intent of this is to lower the interior humidity,
but being mechanically sympathetic i would have preferred the
compressor and fan to shut off periodically... ugh!!


digital voltmeter:

the v8 doesn't have a voltmeter in the dash, but channel 11 is just
that.  channel 12 counts the number of times voltage fell below 9.5
volts.. time for a new battery indicator.  handy!

anybody know any hacks around the first 2 problems?  this is the
second generation system found on the later cars.  mine is a 1990 v8.


eliot