SECTION 10-H – 1953 BUICK SIGNAL SYSTEM
NOTE: For Series 40 6-volt systems refer to Section 10-H in the 1952 Buick Shop Manual.
10-52 1953 BUICK HORNS AND CONTROL CIRCUIT
1953 Buick Horns and Relay
Two Delco-Remy electrically operated vibrator type horns are mounted in front of the radiator. Both 1953 Buick horns are operated simultaneously by an adjacent horn relay which is controlled by the horn button on steering wheel. The left hand horn is high pitched (380-4 00 cycles) and the right hand horn is low pitched (302-323 cycles), so that together they produce a pleasing blended tone.
The 1953 Buick horn relay is an electrical switch which closes the circuit between the battery and the horns when the horn button is pressed, and opens the circuit when the button is released. The relay permits control of the horns with a small amount of current passing through the horn button contacts. The high current required by the horns would cause arcing and burning of these contacts.
When the 1953 Buick horn button contacts are closed, a small amount of current flows through the relay winding to ground at the horn button. This magnetizes the relay core, which attracts the flat steel relay armature. The armature has a contact point which makes contact with a stationary point to close the horn circuit. When 1953 Buick horn button is released, current stops flowing through relay winding so that the core loses its magnetism; the armature spring then causes contact points to be separated.
1953 Buick Horn Buttons
The 1953 Buick horn button used with the flexible spoke steering wheel includes an operating ring and a contact plate mounted in the steering wheel cap base. When the operating ring is pressed it touches the contact plate to close the circuit to ground, thus completing the relay circuit and causing the horns to operate.
The monogram and bez el assembly is held in the steering wheel cap base by three springs. The assembly may be removed by inserting a small screw driver in a notch provided in the cap base and prying against the bezel. When the monogram and bezel assembly are removed, the operating ring and wheel base assembly may be removed by removing the three screws which attach the wheel base to the steering wheel hub.
The 1953 Buick horn button used with the solid spoke steering wheel has a cap with a rubber retainer in its rim which snaps over the rim of a contact cup mounted in the wheel hub. The cap may be pried out with a thin bladed tool and the contact cup and other parts may then be removed by removing the three attaching screws and insulating spacer bushings.
Adjustment of 1953 Buick Horns
When 1953 Buick horns fail to blow first check wiring circuit (par. 10-12, c) before attempting to adjust horns. If 1953 Buick horns are at fault, or tone is poor, adjust each horn for specified current draw as follows:
- Remove horn from car and remove the back shell, which is crimped over the collar at four points.
- Inspect air gap between armature and core for steel burrs or other foreign matter; clean out if present. This may correct the trouble. If it does not, proceed as follows:
- Connect an ammeter in series with the horn and a fully charged 12-volt battery to measure the current draw when horn blows. Current draw should be as follows:
- Left (high note) horn: 9.5 Amps. min.
- Right (low note) horn: 10.5 Amps. min.
- Adjust to specified current draw, if necessary, by loosening lock nut and turning contact point adjusting nut clockwise to decrease or counterclockwise to increase current draw. See figure 10-75.
This adjustment is very sensitive, and adjusting nut should not be moved more than one-tenth turn at a time, then locked with nut each time before trying the horn.
- Increasing the current draw increases the horn volume. Too much current will produce a high cut-in voltage, which will cause a sputtering sound and may cause horn to stick in cold weather.
- After each horn has been adjusted individually, sound both horns together to check for proper blend of tone.
- After horn adjustment is completed install the back shell. Make sure that back shell is seated against horn collar all around, then crimp tangs of shell over collar at four points.
- When horns are reinstalled, connect a voltmeter between each horn terminal and ground to check voltage when horns are blown. This should be at least 7 volts.
10-53 ADJUSTMENT OF 1953 BUICK HORN RELAY
Three checks and adjustments are required on the 1953 Buick horn relay: air gap, point opening, and closing voltage. These should be made in the following order:
- Remove horn relay from car then remove relay cover.
- Push relay armature down until contact points just touch, then check air gap between armature and end of core using feeler gauges. Air gap should be .014″. Adjust gap to .014″, if necessary, by bending the lower point support. See figure 10-76.
- With armature free, check contact point opening, using feeler gauges. Point opening should be .025″. Adjust opening to .025″, if necessary, by bending the upper armature stop. See figure 10-77.
- Connect the positive terminal of a 12-volt battery to the battery (middle) terminal of horn relay.
- Using a variable rheostat of 10 ohms minimum and a capacity of 2 amperes, connect one lead to the negative post of battery. Set rheostat to provide full resistance, then connect the other lead to the “S” terminal of relay.
- Connect a 12-volt test lamp between negative post of battery and the “H” terminal of relay.
- Connect positive lead of low reading voltmeter to the battery (middle) terminal of horn relay and connect negative lead of voltmeter to the “S” terminal of relay.
- Slowly decrease resistance until the test lamp lights, note the voltmeter reading, then turn rheostat to full resistance. Closing voltage should be 5.5 to 7.5 volts.
- If closing .voltage is not within specified limits, bend the armature spring post as required. Bend down to increase closing voltage or bend up to decrease closing voltage. See figure 10-78.
- After proper closing voltage is obtained, install relay cover. Install relay on car and connect wires as shown in wiring circuit diagram in Section 10-J.
10-54 1953 BUICK DIRECTION SIGNAL LAMPS AND SWITCH
1953 Buick Direction Signal Lamps and Indicators
The front directional signal light is produced by the 32 CP filament in the bulb mounted in the front parking lamp. The rear directional signal light is produced by the 32 CP lamp bulb in the separate signal lamp mounted below the tail and stop lamp on each rear f ender.
When the ignition switch is turned on and the direction signal switch is manually operated to indicate a turn, the front and rear signal lights flash on and off on the side of car for which a turn is indicated. The flashing of signal lights is caused by a Tungsol flasher which is connected into the proper signal light circuit by contacts made in the direction signal switch when switch is set for a turn.
When the 1953 Buick direction signal lights are flashing, a signal indicator bulb on instrument panel also flashes, producing a small arrow of green light to indicate the direction for which the signal has been set.
1953 Buick Direction Signal Switch Operation
The direction signal switch and its operating mechanism are enclosed in a switch housing on the steering column just below steering wheel.
The switch is operated by a lever projecting from the left side of switch housing. Moving the operating lever clockwise sets the switch to indicate a right turn and moving lever counterclockwise indicates a left turn.
The operating lever is locked by a set screw into a stub shaft anchored to a plate in switch housing which operates the switch. The stub shaft fits into a recess in the housing to provide a bearing or pivot point for the lever and plate. A slot in right side of the lever plate engages the bakelite handle of the switch which is mounted in the housing below the lever plate. A detent spring mounted in the housing bears against a roller mounted on the lever plate to hold the plate in whatever position it may be set. Bosses in the housing provide stops for the plate when set for either turn. See figure 10-79.
The trip mechanism for returning the switch to the “off” position after a turn is completed consists of a cam on the steering wheel hub, and two spring loaded triggers mounted on the lever plate. The cam is a round steel stamping having two projecting ribs, and it is rigidly mounted on the wheel hub. When the switch is in the “off” position, the lever plate is centered around the cam so that the ribs of cam cannot contact either trigger when steering wheel is turned. See figure 10-79.
When the operating lever is moved clockwise to set the switch for a right turn the lever plate is moved down, thereby moving the switch handle down and also bringing the upper trigger into the path of the cam ribs. As the steering wheel is turned right and a cam rib contacts the trigger, the trigger rotates to permit the cam rib to pass without interference. The coil spring then returns the trigger to its original position. See figure 10-80.
As the steering wheel is turned left at completion of the right turn the cam rib again contacts the trigger, which is prevented from rotating out of the way by a flat spring mounted on the lever plate. The cam rib pushes against the trigger to move the lever plate and switch back to the “off” position. See figure 10-81.
The flat spring cushions the shock as the cam rib contacts the trigger, and it would also permit the trigger to rotate out of the way and let the steering wheel turn in case anything held the lever and plate from returning to “off” position.
The same action takes place when the switch is set for a left turn, except that the lever plate is moved up to bring the lower trigger into contact with the cam. If the switch is erroneously set to indicate a turn in one direction and the turn is made in the opposite direction, the opposite rib of cam will contact the trigger and return the switch to “off” position as the wrong turn is started.
Replacement of 1953 Buick Signal Switch Parts
- Remove steering wheel.
- Use a 1/8″ hex (Allen) wrench to loosen the operating lever set screw and remove lever. See figure 10-79. NOTE: If only the lever requires replacement remove horn button only, then insert wrench through a puller hole in steering wheel to loosen the set screw.
- Remove lever plate detent spring, then lift the lever plate out of switch housing.
- If switch is to be replaced, disconnect signal switch wires from fuse block under the cowl, remove switch attaching screws, then carefully pull the switch and wiring harness assembly out through switch housing.
- When switch and wiring harness assembly is installed, connect switch wires to fuse block as shown in the chassis wiring circuit diagrams in Section 10-J.
- Before installing the lever plate, apply a light coat of Lubriplate to the top of signal switch and ‘to the stub shaft on lever plate.
- Install steering wheel.
1953 Buick Direction Signal Lamp Circuits
Since the 1953 Buick direction signal lights are independent of the headlamp lighting switch and thermo circuit breaker, the wiring circuits are protected by a “Direction Signal” fuse on the fuse block under the cowl. The Tungsol flasher is also mounted on the fuse block, which serves as a terminal block between the signal switch and the chassis wiring.
The 1953 Buick direction signal lights are independent of the parking and stop light circuits, and the indicator lamp bulb sockets are grounded to the instrument panel.
Figures 10-82, 10-83, and 10-84 show the direction signal circuits when signal switch is set for No Turn, Right Turn, and Left Turn.
1953 Buick direction signal switch wiring is also shown in the chassis wiring circuit diagrams in Section 10-J.