Buick LeSabre 1965 Service Manual page 856

ACCESSORIES
ELECTRO-CRUISE 1 1 - 1 2 3
SECTION 11-E
ELECTRO-CRUISE
CONTENTS OF SECTION 11 -E
Paragraph
Subject
11-22 D e s c r i p t i o n and O p e r a t i o n
of E l e c t r o - C r u i s e . . . .
Page Paragraph Subject Page
11-23 Electro-Cruise Service Procedures . 11-129
11-123 11-24 Electro-Cruise Trouble Diagnosis . . 11-133
1 1 - 2 2 DESCRIPTION AND
OPERATION OF
ELECTRO-CRUISE
a. Description
The Electro-Cruise is a constant
speed regulating system capable
of accurate control of car speed
over a wide range of road loads.
Within the limits of the system,
a speed range of 30 to 90 MPH
can be accurately held within
2-1/2 MPH of the particular
speed setting. Unlike a constant
throttle device which locks the
throttle in a selected position re-
sulting in speed variation accord-
ing to the varying road conditions,
the Electro-Cruise system com-
pares a measurement of car
speed with the selected speed to
maintain the selected speed under
varying road conditions.
The Electro-Cruise is offered as
o p t i o n a l equipment on 45000,
46000, 48000 and 49000 Series.
The Electro-Cruise is an elec-
tronic-pneumatic system which
consists of a power unit connected
to the throttle linkage through a
bead chain; an amplifier and relay
control assembly; a speed trans-
ducer which is an integral part
of the speedometer; an engage-
ment switch and CRUISE lamp;
and a cruise release switch lo-
cated on the brake pedal arm
support bracket.
In operation, electrical signals
from the speed transducer oper-
ate a vacuum switch which ports
engine vacuum to the power unit.
Through constant signals from the
speed transducer, the power unit
assumes its proper position to
control the throttle opening. The
electronic amplifier, engagement
switch and brake release switch
are the a u x i l i a r y components
necessary to engage and disen-
gage the system.
1. SPEED SETTING - The speed
setting pointer moves over the
existing speedometer scale and is
set to the desired speed by rotat-
ing the speed setting knob at the
bottom of the speedometer. See
figures 11-171 and 11-172. The
desired speed can be set either
with the system engaged or dis-
engaged; however, car speed will
only be controlled by the Electro-
Cruise when the system is en-
gaged. If the speed setting is
changed while the system is en-
gaged, car speed will increase or
decrease automatically to coin-
cide with the desired setting.
2. ENGAGEMENT - The engage-
ment switch lever and CRUISE
lamp assembly is located to the
right of the speedometer on 49000
Series cars and fully controls the
engagement of the system. See
Figure 11-172. On 45000, 46000
and 48000 Series the unit will be
located on the speedometer head.
To engage the system, it is nec-
essary only to depress the en-
gagement lever or knob until the
CRUISE lamp lights indicating the
Electro-Cruise is in operation.
If car is at or above the speed
setting when the engagement lever
is depressed, the CRUISE lamp
will come on immediately. If car
speed is below the speed setting,
it is necessary to hole the en-
gagement lever forward until the
car has accelerated to the set
speed to cause the CRUISE lamp
to light. Use of the accelerator
pedal is not necessary to obtain
the desired set speed with the
engagement lever held forward
as the Electro-Cruise will auto-
matically accelerate the car to
this speed.
However, for faster acceleration
to the set speed, the car may be
brought up to speed by means of
the accelerator pedal and then
engaged by depressing the en-
gagement lever when the car is
within 2-1/2 MPH of the set speed
or above.
3. DISENGAGEMENT - The
Electro-Cruise can be disengaged
by a touch of the brake pedal, by
pulling the engagement lever
or knob rearward or by turning
the ignition switch to the OFF or
LOCK positions. Each of these
will restore full accelerator pedal
control to the driver. Once the
Electro-Cruise has been disen-
gaged, it is necessary to re-
e n g a g e it again u s i n g the
engagement lever to restore op-
eration of the system.
4. OVERRIDE - Electro-Cruise
system in no way prevents or
hinders increases in throttle
angle through use of the acceler-
ator pedal. Therefore, if a higher
speed is momentarily desired
when the system is in operation,
the accelerator pedal may be de-
pressed in the normal manner to
o v e r r i d e the Electro-Cruise.
When the accelerator pedal is
released, the Electro-Cruise will
again maintain the desired set
speed without re-engagement.