This is the cruise control servo unit. A steel cable pulls on the gas pedal.



Inside the servo the steel cable connects to a pulley on the output shaft. The shaft
only turns about a half rotation.


The servo gets its commands through this electrical connector.


These are the signals on each pin.


This is a composite of the entire cruise control system. Pin 9 deserves special consideration. Assume the shifter was accidentally bumped into neutral (or the clutch pushed in),
the car would start to slow down. The VSS would detect this slow down and send a signal to the cruise servo to increase engine RPM. Because the car is in neutral it continues
to slow down. The servo would very quickly drive engine into the rev limiter (6800 RPM). The Transmission Range Switch (or Clutch Pedal Position switch for manuals) prevents
this from happening. In neutral, the TRS or CCP switch sends a ground through the hold-in winding of the starter to pin 9. That ground signal immediately cancels the servo operation.
The full-size drawing can be downloaded at: https://www.dropbox.com/s/cwoipose9f...odule.jpg?dl=0


One quick anecdote. Although the cruise SET switch on the wiper stalk worked fine when my car was new,
it became unreliable over time. By 2017 it was barely working at all. I ordered a very expensive switch
assembly from RockAuto. When the old switch was on the bench I noticed one of wires was not soldered
to the circuit board. I reflowed the joint and the SET switch has worked flawlessly ever since. I sent the
unused switch assembly back to RockAuto saving myself several hundred dollars.