Ford COUGAR 1968 Shop Manual page 727

BART 16-3-
Speed
C o w f ~ ~ l
Section Page
1 Description and Operation
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16-41
Description
........................................
16-41
Operation
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16-4 1
..................................
2 Diagnosis and Testing 16-42
Diagnosis..
..............................................
16-42
Testing
...................................................
16-42
Instrument Panel Switch Test
...................
16-42
...
Turn Signal Lever Set-Speed Switch Test.
16-42
Brake Release Relay Test
........................
16-42
Section
Page
Regulator Assembly Test
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16-42
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Servo Assembly Test 16-43
Brake Stoplight Switch Test
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16-43
3 Removal and Installation
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16-43
On-Off Switch
.........................................
16-43
Turn Signal Lever Set-Speed Switch
.............
16-43
Regulator Assembly
..................................
16-43
Brake Release Relay
.................................
16-44
Servo Assembly (Bellows)
...........................
16-44
1 DESCRIPTION AND OPERATION
DESCRIPTION
The automatic speed control system
is a driver operated speed regulating
device designed for use on turnpike
or other open road driving. It can
be used to maintain a constant ve-
hicle speed from 30 to 80 mph on
both hilly or level roads. In
RO
in-
stance does the system restrict or af-
obtained b y . depressing the accelera-
I
tor. When the accelerator is released.
,
fect available engine rpm or sacrifice
the vehicle will return to the previous-
ly set speed automatically. This over-
ride feature allows complete control
of vehicle speed without disrupting
the memory of the speed control
system. When the brakes are applied
the memory of the system is cancelled
and the speed must be reset.
The vehicle speed may also be
controlled by use of the two position
set-speed switch on the end of the
turn signal lever. Pressing the set-
speed switch to the first detent acti-
vates the speed control system and
increases the vehicle speed as long
as the switch is depressed to the first
detent. When the switch is released,
the vehicle will maintain the new speed.
When the set-speed switch is pressed
to the coast position (second detent-
1
I
!
all the way in), the system is disen-
gaged until the button is released.
The vehicle speed at the time of but-
ton release will be maintained provid-
ing it is above the minimum speed of
30 mph. The system can be shut off
by the ON-OFF switch, located on the
lower edge of the instrument panel
below the ignition switch.
performance.
The system consists of a speed con-
trol regulator assembly, a brake re-
lease relay, an ON-OFF switch, a two
position turn signal lever (set-speed)
switch, a servo assembly (bellows),
upper and lower speedometer cables,
OPERA'I'ION
and the necessary wires, vacuum
:
hoses, and linkage to connect the
components for proper operation.
When the system is in operation,
additional speed for passing can be
Refer to Group 19 for the Speed
Control wiring diagrams.
When the ignition switch is O N
and the speed control ON-OFF switch
is pulled out to the on position, elec-
trical power is supplied to the turn
signal lever set-speed switch and the
speed control regulator assembly.
Within the regulator assembly, elec-
trical power is supplied to the vacuum
solenoid valve holding circuit, and
stops at that point.
Vehicle speed is transmitted to the
governor in the regulator assembly
with a speedometer cable which is
connected to the vehicle transmission.
As the speed of the vehicle is increas-
ed, the governor fly-weights are forc-
ed outward by centrifugal force. AS
the vehicle speed reaches approxima-
tely 30 mph, the governor causes the
low speed switch point contacts to
close. This makes the speed control
system ready for operation.
When the vehicle speed reaches ap-
proximately 30 mph or faster, the
turn signal lever set-speed switch but-
ton should then be depressed to the
first detent for speed control opera-
tion. When the set-speed switch but-
ton is depressed to the first detent,
the advance solenoid coil is energized.
This closes the valve, blocking the
atmospheric air port to the regulator
assembly. At the same time, the sole-
noid valve coil is energized and opens
the regulator assembly port to the
intake manifold. This creates a vacuum
in the bellows and increases the
throttle opening and vehicle speed.
When the solenoid valve coil is ener-
gized, the power feed circuit to the
coupling coil (clutch) is also ener-
gized but the circuit is not complete
until grounded by the advance sole-
noid valve. The advance solenoid
valve must open to complete the
coupling coil (clutch) circuit.
.After the desired vehicle speed
has been reached, the set-speed switch
button should be released. When the
button is released, the advance sole-
noid coil is de-energized and opens
the valve, allowing entry of atmosph-
eric air into the regulator assembly.
When the valve opens, the ground cir-
cuit to the coupling coil (clutch) is
completed and the coil is energized
along with the solenoid valve coil.
These two coils remain energized
through the holding circuit. When the
coupling coil is energized, the gover-
nor is locked to the orifice metering
valve. The governor, through vehicle
speed, allows a metered amount of
atmospheric air to equalize vacuum
in the bellows and stabilize the set
vehicle speed.
I f the vehicle speed is reduced
as when climbing a hill, the governor
will reduce the orifice opening size.
This will restrict the entry of atmos-
pheric air and increase the vacuum
drawn from the bellows. This will col-
lapse the bellows and increase the
carburetor throttle plate opening and
vehicle speed. If the vehicle speed
is increased, as when descending a
hill, the reaction of the governor is
the opposite and the orifice size is
increased. This allows more atmos-