CHASSIS ELECTRICAL 199
the parking brake warning light switch, and a
relay, which is located between the instru-
ment cluster wiring and the switch on the
parking brake. A diode is used to prevent
feedback into the parking brake warning cir-
cuit.
On cars having automatic transmissions, the
seat belt warning circuit is wired through the
ignition switch and the combination back-up
lamp/neutral safety switch.
With the ignition key in the "RUN" posi-
tion, a weight of 40-50 Ibs. on the driver's or
passenger's seat pressure-sensitive switch)
energizes the circuit when the parking brake
is released (MAT) or the gear selector placed
in a forward drive range (A/I).
A warning light will glow and a buzzer will
sound with the circuit energized, unless the
seat belts are withdrawn from the retractors
and fastened over the kps of the two out-
board front seat occupants.
Seat Belts/Starter Interlock
System
As required by law, all 1974 and some 1975
Chevrolet passenger cars cannot be started
until the front seat occupants are seated and
have fastened their seat belts. If the proper
sequence is not followed, e.g., the occupants
fasten their seat belts and then sit on diem,
the engine cannot be started.
If, after the car is started, the seat belts are
unfastened, a warning buzzer and light will
be activated in a similar manner to that de-
scribed for 1972-73 models.
The shoulder harness and kp belt are per-
manently fastened together, so that they both
must be worn. The shoulder harness uses an
inertia-lock reel to allow freedom of move-
ment under normal driving conditions.
NOTE:
This type of reel locks up when the
car decelerates rapidly, as during a crash.
The lap belts use the same ratchet-type re-
tractors that the 1972-73 models use.
The switches for the interlock system have
been removed from die kp belt retractors and
placed in the belt buckles. The seat sensors
remain the same as those used in 1972-73.
For ease of service, the car may be started
from outside, by reaching in and turning the
key, but without depressing the seat sensors.
In case of system failure or for service, an
override switch is located under the hood.
This is a "one start" switch and it must be
reset each time it is used.
DISABLING THE INTERLOCK SYSTEM
Since the requirement for the interlock sys-
tem was dropped during the 1975 model year,
these systems may now be legally disabled.
The seat warning light is still required.
1. Disconnect the battery ground cable.
2. Locate die interlock harness connector
under die left-side of die instrument panel
on or near die fuse block. It has orange, yel
low, and green leads.
3. Cut and tape die ends of die green wire
on die body side of die connector.
4. Remove die buzzer from die fuse block
or connector.
5. Reconnect the battery ground cable.
LIGHTING
Headlight Sealed Beams
REMOVAL AND INSTALLATION
1. Open die headlight panel to die open
position.
2. Remove die headlight bezel retaining
screws and remove the bezel.
3. Disengage die spring from die retain
ing ring and remove die two attaching screws.
NOTE:
Do not touch the adjusting screws.
The retaining ring screws are the screws
which go through the closed holes in the
retaining ring. The adjusting screws go
through the slotted open holes in the re-
taining ring and adjust the angle of the
mounting ring behind the headlight sealed
beam.
Headlamp assembly—1963-67
