Operation & Diagrams
The basic parts of
the sequential system are:
Turn Signal Switch (located in the
Steering Column)
Turn
Signal Indicator Relay (mounted to the Steering Column Support)
Turn Signal Relay (located
under the Package Tray, in the Trunk)
Flasher or Sequencer Unit (mounted
with the Turn Signal Relay)
Stop Light Relay (also mounted with the Sequencer and Turn
Signal Relay)
SEQUENTIAL TURN SIGNAL CIRCUIT OPERATION
When the Turn Signal Lever is actuated, a circuit is
completed to the Turn Signal Relay and to the respective right or left side
solenoid in that relay. A set of four contact points is actuated by each solenoid to connect
the respective rear lights to the flasher and motor circuit. (Three contacts connect the
three rear lights and one contact connects the front turn signal light.)
The following wires are connected together at the Turn Signal Switch when
lifted to the right hand position: (694, 362) and (8, 441, 458). In
the left-hand position, wires (694, 363) and (8, 440, 458) are connected.
When the Turn signal Switch is actuated, either right or left, the circuit
energizes the Flasher Motor which turns the flasher cam. As the cams rotate, the three
sets of contacts are closed in sequence and the three rear stop lights are
illuminated in sequence beginning at the inboard light, then the center light
and then the outboard light. All three lights go out at the same time and the
cycle is repeated as long as the turn signal switch is closed. The front parking light bulb flashes at the same time as the center rear
bulb. When the Turn signal Switch is canceled, all the light bulbs go out immediately.
TROUBLESHOOTING TESTS
(assuming all chassis grounds are solid to the battery Neg): If the bulb and socket and wiring has continuity to the Turn Signal Relay and
all of the lights but one operate, then make a test for power at the relay
terminal of the bulb in question. If no power is available, the Turn Signal
Relay contact is defective. This test is made with the ignition switch
ON and the Turn Signal Switch in the proper position, up or down.
ONE SET OF TURN SIGNAL LIGHTS DOES NOT OPERATE BUT BRAKE LIGHTS OPERATE Test for power at the Turn Signal Switch disconnect-terminals with the Turn Signal
Lever in the center 'non-functioning' position and the ignition Key Switch turned ON. If there is
no power at the terminals leading to the motor, Turn Signal Indicator Relay, or
the Turn Signal Relay, the Turn Signal Switch is defective. If power is
available to all these terminals, the trouble can be isolated to the wire
leading to the Turn Signal Relay coil or to the relay unit. Test
for power at the turn signal relay disconnect at the terminal leading from the
switch. If power is not available, the wiring is open between the switch
and the relay. If power is present, the turn signal relay is defective. This wire energizes the relay coil, which switches the circuit from the stop light wires to the turn signal
wires.
* The Stop Light Relay was only used in early production models.
ONE OR BOTH SETS OF STOP LIGHTS DO NOT OPERATE BUT TURN SIGNAL LIGHTS OPERATE If all stop lights do not operate, the problem can be at the stop light switch,
Stop Light Relay, Turn Signal Relay or the wires between the three
components may be open.
Test for power across the Stop Light Switch terminals with the Brake
Pedal depressed. If there is no power, the Stop Light Switch is defective.
If there is power, test for power at the Stop Light Relay to determine if it
has a good ground connection and if it is operating. If there is no power, there
is a defect in the wiring between the Stop Light Switch and the Stop Light Relay.
If there is power and the relay is functional, check the wire and
connections between the Stop Light Relay and the Turn Signal Relay. If the
wire is good, there is a defective connection inside the Turn Signal Relay.
ALL TURN SIGNAL LIGHTS DO NOT OPERATE ALL PARKING LIGHTS AND STOP LIGHTS DO
OPERATE
This problem will require visual, audible, and power tests at all of the
sequential turn signal components. Since the stop lights operate, we can
temporarily eliminate the Turn Signal Relay as the trouble spot. Using the
circuit diagrams as reference, test for power at the Turn Signal Switch
first in both left and right positions to determine if power is available from
it to the Turn Signal Indicator Relay, the Flasher and Motor Unit and the Turn Signal relay. All tests are made with ignition
Kew Switch and Turn Signal Switch, ON. After
eliminating the Turn Signal Switch as the fault, check power at the
Turn Signal Indicator Relay to determine if it is operating properly. Next, go
to the Flasher and Motor Unit and test all of its leads for power. The
last possible unit is the Turn Signal Relay.
Test the components in this order: Test the power source and then the power output
before assuming the component is defective. The fault may be in the
wiring between components.
EMERGENCY WARNING FLASHER
The flasher and motor unit schematic shows one set of contacts
and one operating coil has been eliminated. This set of contacts was used as the
parking switch for the sequential motor, the motor will now park in any
position.
The switch for the emergency warning flasher circuit has been relocated to
the right-hand side of the steering column, opposite the turn signal switch
lever. Both switches are in a one-unit assembly.
The turn signal circuit can only be operated when the
ignition switch is in the ACC position or the ON position. The emergency warning
flasher circuit receives power directly from the battery through a separate
circuit breaker and can be operated independently of any other circuit. Illustration 17001.3-12 shows the
emergency warning flasher circuit. The switch is shown in the OFF position and the
relays in the de-energized position.
OPERATION 2. Wire #440 completes the circuit to the left-hand solenoid in the turn
signal relay. This connects the left-hand front and rear lights to the flasher
motor circuit. 4. Wire #458 completes the circuit through the coil and contact points
of the turn signal indicator relay. Wire #459 completes the circuit which
runs
the Flasher Motor.
5. Wire #694 completes the circuit through the contact points of relay A and
on through wires 362 and 363 to the right- and left-hand indicator bulbs.
6. Since the contact points of relay B are closed, wires 4364, 437A, and 438A
are in effect a single wire circuit. This combines the three sequential
signals, coming from the flasher, into a single flashing signal.
The flashing signal is then sent through the closed points of the Turn Signal
Relay to all six rear lights and two front lights. The two Indicator Lights on
the dash panel go out each time the current draw from the eight exterior lights
causes the Turn Signal Indicator Relay contact points to open. The dashboard Indicator
Lights flash at the same speed as the exterior lights, but at opposite times.
The stop light
circuit is wired into the turn signal circuit.
ONE LIGHT, EITHER FRONT OR REAR, DOES NOT OPERATE
First, eliminate the possibility of any problems which can be found by a visual
inspection and the possibility of a burned out bulb. The only possible part left
to check is the Turn Signal Relay in the taped package.
This problem can be isolated to the turn signal switch, the turn signal relay or
the wiring from the switch to the relay.
If one set of brake lights does not operate and the turn signals do operate,
the problem must be a defective Turn Signal Relay.
1. Turn Signal Switch
2. Turn Signal Indicator Relay
3. Flasher and Motor Unit
4. Turn Signal Relay
The emergency warning flasher circuit utilizes the sequential flasher and
motor unit as the flashing element instead of a heavy-duty flasher can. In
addition, the system requires two double-pole relays versus three relays in
the older system.
When the switch is pushed in, or in the ON position, several circuits are
completed:
1. Wire #441 completes the circuit to the right-hand solenoid in the turn
signal relay. This connects the right-hand front and rear lights to the flasher
motor circuit.
3. With the ignition switch on, wire #514 de-energizes relay coils A and B
through normally closed contacts.
Return to Squarebirds Home
