Cruise Control Diagnostics

["Smith, Kirby A" <kirby.a.smith@lmco.com>]

Quatrophiles:

Some apparently anomalous behavior by my 1988 90q cruise control (CC) led me
to investigate it this past weekend.  After checking that vacuum was being
held by the throttle control and that the vacuum could be released by both
brake and clutch pedals, I dived into the Bentley for additional
information.  After overcoming the strange numerical order of the sections,
I found 27.19 et al to be cursory; there were no diagnostic tests listed
other than the vacuum test and backup light test.  However, the electrical
schematic CC section shows a factory test connector.  So my questions:

Is lack of diagnostic information an oversight by Bentley, or is the CC
untestable other than demonstrating performance on the road?

Where is the control module exactly?  I've been behind my glove compartment
several times, and never noticed this module, not to be confused with the
fuel injection or ignition CPUs.

                .... Kirby   (Kirby A. Smith)
                              2 x 1988 90q
                          New Hampshire USA