5000 S A/C, Cruise Control and OBC Questions

[Peter Rossato <peterrossato@erols.com>]

I have a 1987 5000S wagon with the 2.2L engine, automatic.  I have three
failures, two of which may even be related, with which I would like to
be helped.

A/C:  The ventilation system blows air through the defroster and
footwell vents only.  If I select defrost, it will only flow from the
defrost vents.  Selecting Econ, Bi-level or Auto have no effect on
ventilation distribution.  I have had the programmer replaced over a
year ago and the one year warranty on it expired (wouldn't youknow it!)
this May.  When Auto is selected, the compresor clutch engages for a few
seconds (less than 5) and then disengages for a about a minute or so
before engaging and repeating the cycle.  I suspect the programmer, but
wonder about a vacuum leak.  Nothing obviously wrong at the condenser
core where the vacuum lines come through the firewall.

Cruise control:  Can't set speed.  It is totally inoperative.  I can not
tell readily if the system is turned on , but it just isn't registering
a set speed command, or it isn't even coming on.  Is there a possible
tie in to the ventilation system problems through the vacuum system?

OBC:  The On Board Computer will not scroll through any function.  I can
not even change the time on the clock.  The switch commands have no
effect what so ever.  I suspected the switch, but I examined it and it
is fine.  I did have a shop replace the speedometer at the same time as
the problem occurred.  I intend to remove the gauge housing and verify
that the OBC is connected behind the tachometer face.  Does this failure
sound typical on Audis or is it likely just a connection problem.  If
the OBC is shot, what are the alternatives to a $520 part from Audi?

There's a lot here, but I would appreciate any and all forms of advice
from the Audi support network.

Thank you.