Slide Switch On (Cruise Command); Pushbutton Depressed - Setting Speed; Pushbutton Released - Maintaining Speed; Coupling Coil And Centering Spring Assembly - Jeep 1979 CJ-5 Technical & Service Manual

CRUISE COMMAND 1H-3
Coupling Coil and Centering Spring Assembly
The coupling coil is the mechanism that gives the
Cruise Command its memory during the resume phase
(fig. 1H-3). When not under the influence of the mag-
netic coupling coil, the rotating vacuum regulator plate
is held in a centered position by the centering spring (fig.
1H-4).
The coupling coil is rotated on its axis by motion of the
governor actuator assembly. When the coil is not ener-
gized, the coupling coil can be rotated without affecting
the position of the rotating vacuum regulator plate.
When energized, the coupling coil captures the regulator
plate and forces it to rotate in unit with the coupling
coil. Slight rotational movement of the vacuum regu-
lator plate uncovers or blocks the vacuum bleed port.
D R I V E
PIN
ADJUSTMENT
ECCENTRIC
7 0 0 6 9
Fig. 1H-3 Coupling Coil and Centering Spring Assembly
The centering spring determines the position of the
rotating vacuum regulator plate over the bleed port dur-
ing the set speed phase (fig. 1H-4). Its adjustment is
accomplished by an eccentric. Adjustments of more
than 1/8 turn of the eccentric should not be attempted.
Slide Switch O N
With the engine running and the ignition switch On,
the Cruise Command relay is energized and current is
supplied to the slide switch (fig 1H-5). When road speed
reaches approximately 30 mph, the governor flyweights
have moved outward enough to close the low speed
switch.
V A C U U M PORT V A C U U M PORT V A C U U M PORT
U N C O V E R E D B L E E D BLOCKED
(CENTEREQ)
Fig. 1H-4 Vacuum Regulator Plate Positions
When the slide switch is moved to the ON position,
current -is supplied through the pushbutton to the cou-
pling coil which is energized. The coupling coil grounds
through the regulator case. Note that the solenoid valve
is in the relaxed position and seals the vacuum source
because no current has yet been supplied to energize the
solenoid valve coil. The system is now ready to be set
provided road speed is above 30 mph, closing the low
speed switch.
Pushbutton Depressed—Setting Speed
When the desired speed is reached, the pushbutton is
depressed momentarily (fig 1H-6). Current to the cou-
pling coil is interrupted, de-energizing the coil and re-
leasing the coupling coil from the vacuum regulator
plate. Spring pressure in the actuator assembly rotates
the freed coupling coil until it is in the position which
corresponds to the selected road speed. The vacuum
regulator plate is moved by the centering spring to its
neutral (calibrated bleed) position. Simultaneously, cur-
rent is supplied to the solenoid valve coil which pulls the
vacuum valve off its seat. The vacuum source begins to
evacuate air from the mixing chamber of the regulator
valve and the bellows.
The vacuum solenoid valve circuit is grounded
through the stoplamp bulbs.
Pushbutton Released—Maintaining Speed
This mode begins when the vacuum solenoid valve
reaches the energized position (fig 1H-7). At that time,
current supplied through the reed switch flows through
the solenoid coil, through the low-speed switch to
ground at the stoplamp bulbs. This current acts to hold
the solenoid in the energized position. When the push-
button is released, the hold-in current maintains the
vacuum solenoid valve in the open position. The vacuum
solenoid valve hold-in circuit grounds through the stop-
lamp bulbs. Current is simultaneously supplied to the