HORN SYSTEM OPERATIONHORN SYSTEM OPERATIONHORN SYSTEM OPERATIONHORN SYSTEM OPERATION

CHAPTER 11CHAPTER 11

HORNSHORNSHORNSHORNS

HORNS OPERATE ON HORNS OPERATE ON ELECTROMAGNETIC PRINCIPLEELECTROMAGNETIC PRINCIPLE

INTERNAL DESIGN DETERMINES INTERNAL DESIGN DETERMINES PITCH OF HORNPITCH OF HORN

SOME HORNS CAN BE ADJUSTED BY SOME HORNS CAN BE ADJUSTED BY CHANGING SPRING TENSIONCHANGING SPRING TENSION

USUALLY A HIGH AND LOW TONEUSUALLY A HIGH AND LOW TONE

HORNHORNHORNHORN

HAS NORMALLY CLOSED POINTSHAS NORMALLY CLOSED POINTS FIELD COIL OPERATES DIAPHRAMFIELD COIL OPERATES DIAPHRAM DIAPHRAM OPENS POINTSDIAPHRAM OPENS POINTS COLUMN OF AIR VIBRATES COLUMN OF AIR VIBRATES

HORN SWITCHHORN SWITCHHORN SWITCHHORN SWITCH

MOST SWITCHES MOST SWITCHES ARE NORMALLY ARE NORMALLY OPEN TYPEOPEN TYPE

DEPEND ON DEPEND ON SLIDER CONTACT SLIDER CONTACT WHEELWHEEL

SPRING CONTACT SPRING CONTACT BUTTONBUTTON

SLIP RING CONTACTSLIP RING CONTACTSLIP RING CONTACTSLIP RING CONTACT

HORN CIRCUITSHORN CIRCUITSHORN CIRCUITSHORN CIRCUITS

TWO METHODS OF TWO METHODS OF HORN CONTROLHORN CONTROL– WITHOUT RELAYWITHOUT RELAY

– POWER SIDE POWER SIDE SWITCHSWITCH

WITH RELAYWITH RELAY– GROUND SIDE GROUND SIDE

SWITCHEDSWITCHED

– MOST COMMON MOST COMMON METHOD USEDMETHOD USED

C324 FIG 11-10C324 FIG 11-10

HORN SYSTEM DIAGNOSISHORN SYSTEM DIAGNOSISHORN SYSTEM DIAGNOSISHORN SYSTEM DIAGNOSIS

HORN PROBLEMSHORN PROBLEMSHORN PROBLEMSHORN PROBLEMS

NO HORN OPERATIONNO HORN OPERATION INTERMITTENT OPERATIONINTERMITTENT OPERATION CONTINOUS OPERATIONCONTINOUS OPERATION POOR SOUND QUALITYPOOR SOUND QUALITY

NO HORN OPERATIONNO HORN OPERATIONNO HORN OPERATIONNO HORN OPERATION VERIFY CONCERNVERIFY CONCERN ROTATE WHEEL ROTATE WHEEL

WHILE DEPRESSING WHILE DEPRESSING HORN BUTTONHORN BUTTON

USE DVOM TO USE DVOM TO PINPOINT PINPOINT PROBLEMS WITH PROBLEMS WITH RELAY SYSTEMRELAY SYSTEM

SWITCH IS ON SWITCH IS ON GROUND SIDE OF GROUND SIDE OF CIRCUITCIRCUIT

L384

HORN SYSTEM HORN SYSTEM WITHOUT RELAYWITHOUT RELAYHORN SYSTEM HORN SYSTEM

WITHOUT RELAYWITHOUT RELAY NO HORN NO HORN

OPERATIONOPERATION SWITCH IS ON SWITCH IS ON

INSULATED SIDE INSULATED SIDE OF CIRCUITOF CIRCUIT

MUST USE LARGER MUST USE LARGER WIRES TO WIRES TO OPERATEOPERATE

AVAILABLE VOLTSAVAILABLE VOLTS

FIG 11-3 L385

POOR SOUND QUALITYPOOR SOUND QUALITYPOOR SOUND QUALITYPOOR SOUND QUALITY

ONE HORN NOT WORKING IN DUAL ONE HORN NOT WORKING IN DUAL SYSTEMSYSTEM

INTERNAL DAMAGE OF HORNINTERNAL DAMAGE OF HORN LOW VOLTAGE TO HORN - SHOULD LOW VOLTAGE TO HORN - SHOULD

BE WITHIN 0.5 VOLTS OF BATTERYBE WITHIN 0.5 VOLTS OF BATTERY USE JUMPER WIRE TO TESTUSE JUMPER WIRE TO TEST CHECK GROUND INTEGRITYCHECK GROUND INTEGRITY

HORN ALWAYS BLOWSHORN ALWAYS BLOWSHORN ALWAYS BLOWSHORN ALWAYS BLOWS

USUALLY CAUSED BY STICKING USUALLY CAUSED BY STICKING SWITCH CONTACTS OR RELAYSWITCH CONTACTS OR RELAY

USE OHMMETER TO TEST FOR USE OHMMETER TO TEST FOR GROUNDED CIRCUITGROUNDED CIRCUIT

USE OHMMETER TO TEST RELAY (OR USE OHMMETER TO TEST RELAY (OR USE VOLTAGE DROP METHOD)USE VOLTAGE DROP METHOD)

HAVE A NICE DAY!HAVE A NICE DAY!HAVE A NICE DAY!HAVE A NICE DAY!

RUFUS’S HORN REPAIR WE DO IT RIGHT!