headlights TOYOTA SUPRA 1986 Service Repair Manual

METER, ANALOG
Current flow activates a magnetic
coil which causes a needle to
move, thereby providing a relative
display against a background
calibration. LED (LIGHT EMITTING DIODE)
Upon current flow, these diodes
emit light without producing the
heat of a comparable light. IGNITION COIL
Converts low±voltage DC current
into high±voltage ignition current
for firing the spark plugs. 1. SINGLE
FILAMENT
GROUND
The point at which wiring attaches
to the Body, thereby providing a
return path for an electrical circuit;
without a ground, current cannot
flow.Current flow causes a headlight
filament to heat up and emit light.
A headlight may have either a
single (1) filament or a double (2)
filament. BATTERY
Stores chemical energy and
converts it into electrical energy.
Provides DC current for the auto's
various electrical circuits.
CAPACITOR (Condenser)
A small holding unit for temporary
storage of electrical voltage.
CIRCUIT BREAKER
Basically a reusable fuse, a circuit
breaker will heat and open if too
much current flows through it. Some
units automatically reset when cool,
others must be manually reset.
DIODE
A semiconductor which allows
current flow in only one direction.
DIODE, ZENER
A diode which allows current flow
in one direction but blocks reverse
flow only up to a specific voltage.
Above that potential, it passes the
excess voltage. This acts as a
simple voltage regulator.
FUSE
A thin metal strip which burns
through when too much current
flows through it, thereby stopping
current flow and protecting a
circuit from damage.
FUSIBLE LINK
A heavy±gauge wire placed in
high amperage circuits which
burns through on overloads,
thereby protecting the circuit.
The numbers indicate the cross±
section surface area of the wires.HORN
An electric device which sounds a
loud audible signal.
LIGHT
Current flow through a filament
causes the filament to heat up
and emit light.
METER, DIGITAL
Current flow activates one or
many LED's, LCD's, or fluorescent
displays, which provide a relative
or digital display.
MOTOR
A power unit which converts
electrical energy into mechanical
energy, especially rotary motion. CIGARETTE LIGHTER
An electric resistance heating
element.
DISTRIBUTOR, IIA
Channels high±voltage current
from the ignition coil to the
individual spark plugs.2. DOUBLE
FILAMENT HEADLIGHTS
FUEL
(for High Current Fuse or
Fusible Link.)
(for Medium Current Fuse)
M
16
GLOSSARY OF TERMS AND SYMBOLS

99
VOLTAGE IS ALWAYS APPLIED FROM THE MAIN FUSE, THROUGH THE HEADLIGHT RELAY (COIL SIDE) TO TERMINAL 5 OF THE
DAYTIME RUNNING LIGHT RELAY (MAIN), TERMINAL 6 OF INTEGRATION RELAY, TERMINAL 14 OF DIMMER SW, DIMMER RELAY
(DAYTIME RUNNING LIGHT RELAY NO. 2) (COIL SIDE), TO TERMINAL 17 OF THE DAYTIME RUNNING LIGHT RELAY (MAIN). WHEN THE
IGNITION SW IS TURNED ON, VOLTAGE FROM THE GAUGE FUSE IS APPLIED TO TERMINAL 2 OF THE DAYTIME RUNNING LIGHT
RELAY (MAIN).
1. DAYTIME RUNNING LIGHT OPERATION
WHEN THE ENGINE STARTS, VOLTAGE FROM TERMINAL ªLº OF THE GENERATOR (ALTERNATOR) IS APPLIED TO TERMINAL 11 OF
THE DAYTIME RUNNING LIGHT RELAY (MAIN). IF THE PARKING BRAKE LEVER IS PULLED UP (PARKING BRAKE SW ON) AT THIS
TIME, THE DAYTIME RUNNING LIGHT SYSTEM DOES NOT OPERATE. WHEN THE PARKING BRAKE IS RELEASED (PARKING BRAKE
SW OFF), A SIGNAL IS OUTPUT FROM TERMINAL 1 OF THE PARKING BRAKE SW TO TERMINAL 8 OF THE DAYTIME RUNNING LIGHT
RELAY (MAIN). THIS ACTIVATES THE DAYTIME RUNNING LIGHT RELAY (MAIN), TURNING ON THE DIMMER RELAY (DAYTIME
RUNNING LIGHT RELAY NO. 2). CURRENT ALSO FLOWS FROM THE MAIN FUSE TO DIMMER RELAY (DAYTIME RUNNING LIGHT
RELAY NO. 2) (POINT SIDE) " HEAD (LH±UPR) FUSE " HEADLIGHT HI LH " HEADLIGHT HI RH " TERMINAL (A)5 OF DAYTIME
RUNNING LIGHT RELAY NO. 3 " TERMINAL (A)3 " GROUND, CAUSING THE HEADLIGHTS TO LIGHT UP AT APPROX. 20 % OF THEIR
NORMAL BRIGHTNESS.
ONCE THE DAYTIME RUNNING LIGHT RELAY (MAIN) HAS BEEN ACTIVATED AND THE HEADLIGHTS LIGHT UP, THE HEADLIGHTS
REMAIN ON EVEN IF THE PARKING BRAKE LEVER IS ENGAGED AGAIN (PARKING BRAKE SW ON).
2. HEADLIGHT OPERATION
WHEN THE LIGHT CONTROL SW IS AT HEAD POSITION AND THE DIMMER SW AT LOW POSITION, CURRENT FLOWS FROM THE
HEADLIGHT RELAY (COIL SIDE) TO TERMINAL 6 OF THE INTEGRATION RELAY " TERMINAL 7 " TERMINAL 13 OF LIGHT CONTROL
SW " TERMINAL 11 " GROUND, ACTIVATING THE HEADLIGHT RELAY.
THIS CAUSES CURRENT TO FLOW FROM THE HEADLIGHT RELAY (POINT SIDE) TO THE HEAD LWR FUSE " HEADLIGHT LO "
GROUND, CAUSING THE HEADLIGHTS TO LIGHT UP AT NORMAL BRIGHTNESS. SIMULTANEOUSLY, CURRENT FLOWS FROM THE
DRL FUSE " DAYTIME RUNNING LIGHT RELAY NO. 3 (COIL SIDE) " GROUND, ACTIVATING RELAY NO. 3.
WHEN THE DIMMER SW IS AT HIGH POSITION, TERMINAL 12 OF THE DIMMER SW OUTPUTS A SIGNAL TO TERMINAL 16 OF THE
DAYTIME RUNNING LIGHT RELAY (MAIN) TO ACTIVATE IT. THIS TURNS ON DIMMER RELAY (DAYTIME RUNNING LIGHT RELAY NO. 2).
SO CURRENT FLOWS FROM DIMMER RELAY (DAYTIME RUNNING LIGHT RELAY NO. 2) (POINT SIDE) TO THE HEAD (LH±UPR) FUSE
" HEADLIGHT HI LH " DAYTIME RUNNING LIGHT RELAY NO. 3 (POINT SIDE) " GROUND, AND FROM THE HEAD (RH±UPR) FUSE "
DAYTIME RUNNING LIGHT RELAY NO. 3 (POINT SIDE) " HEADLIGHT HI RH " DAYTIME RUNNING LIGHT RELAY NO. 3 (POINT SIDE)
" GROUND, CAUSING THE HEADLIGHTS TO OPERATE AT HI.
WHEN THE DIMMER SW IS AT FLASH POSITION, CURRENT FROM THE HEADLIGHT RELAY (COIL SIDE) FLOWS TO TERMINAL 14 OF
THE DIMMER SW " TERMINAL 9 " GROUND, ACTIVATING THE RELAY. SIMULTANEOUSLY, CURRENT FROM THE HEADLIGHT RELAY
(POINT SIDE) FLOWS TO HEADLIGHT LO, LIGHTING UP HEADLIGHT LO AND ACTIVATING DAYTIME RUNNING LIGHT RELAY NO. 3.
THEN TERMINAL 12 OF THE DIMMER SW OUTPUTS A SIGNAL TO TERMINAL 16 OF THE DAYTIME RUNNING LIGHT RELAY (MAIN),
ACTIVATING THE DAYTIME RUNNING LIGHT RELAY (MAIN) SO THAT CURRENT FLOWS TO HEADLIGHT HI LIKE IT DOES FOR HIGH
POSITION. THIS CAUSES ALL HEADLIGHTS TO LIGHT UP.
D 6 DAYTIME RUNNING LIGHT RELAY (MAIN)
15±GROUND : ALWAYS APPROX. 12 VOLTS
2±GROUND : APPROX. 12 VOLTS WITH THE IGNITION SW AT ON POSITION
13±GROUND : ALWAYS CONTINUOUS
5±GROUND : APPROX. 12 VOLTS WITH THE DAYTIME RUNNING LIGHT SYSTEM
DOES NOT OPERATE OR LIGHT CONTROL SW AT OFF OR TAIL POSITION
(WITH THE CONNECTOR IS DISCONNECTED, ALWAYS APPROX. 12 VOLTS)
8±GROUND : CONTINUOUS WITH THE PARKING BRAKE LEVER RELEASED
SYSTEM OUTLINE
SERVICE HINTS