[s-cars] @#$% Cruise Control

[calvinlc at earthlink.net]

OK guys, I have followed the Bentley procedure to the letter to diagnose my
cruise control issue.  Everything passes which indicates replace the
controller.  I have tried 3 different controllers, none of which work
consistently.  Once in a blue moon it will actually work.  Everything in the
Bentley Procedure is bulletproof with the possible exception of two things.

1) One step says to monitor voltage between pin 8 and pin 5 above 20 mph and
make sure it is 12V.  I have 12V there all the time with the ignition on.
Looking at the schematic I would expect 12V there all the time, it looks
like it is coming straight from the fuse.
2) It doesn't really tell you much about checking the speedometer signal.  I
see 2ms or so pulses coming down from 10V on this signal.  The signal never
quite makes it to ground, only about 1V or so, does anyone know if this is
normal?

I am at my wits end and I know at this point I know more than 90% of all
mechanics about this problem so I don't think that's going to help me much.
Please Help!  Thanks!

--Calvin