1. HORN SYSTEM OPERATION CHAPTER 11

2. HORNSHORNS n HORNS OPERATE ON ELECTROMAGNETIC PRINCIPLE n INTERNAL DESIGN DETERMINES PITCH OF HORN n SOME HORNS CAN BE ADJUSTED BY CHANGING SPRING TENSION n USUALLY A HIGH AND LOW TONE

3. HORNHORN n HAS NORMALLY CLOSED POINTS n FIELD COIL OPERATES DIAPHRAM n DIAPHRAM OPENS POINTS n COLUMN OF AIR VIBRATES

4. HORN SWITCH n MOST SWITCHES ARE NORMALLY OPEN TYPE n DEPEND ON SLIDER CONTACT WHEEL n SPRING CONTACT BUTTON

5. SLIP RING CONTACT

6. HORN CIRCUITS n TWO METHODS OF HORN CONTROL –WITHOUT RELAY –POWER SIDE SWITCH n WITH RELAY –GROUND SIDE SWITCHED –MOST COMMON METHOD USED n C324 FIG 11-10

7. HORN SYSTEM DIAGNOSIS

8. HORN PROBLEMS n NO HORN OPERATION n INTERMITTENT OPERATION n CONTINOUS OPERATION n POOR SOUND QUALITY

9. NO HORN OPERATION n VERIFY CONCERN n ROTATE WHEEL WHILE DEPRESSING HORN BUTTON n USE DVOM TO PINPOINT PROBLEMS WITH RELAY SYSTEM n SWITCH IS ON GROUND SIDE OF CIRCUIT L384

10. HORN SYSTEM WITHOUT RELAY n NO HORN OPERATION n SWITCH IS ON INSULATED SIDE OF CIRCUIT n MUST USE LARGER WIRES TO OPERATE n AVAILABLE VOLTS FIG 11-3 L385

11. POOR SOUND QUALITY n ONE HORN NOT WORKING IN DUAL SYSTEM n INTERNAL DAMAGE OF HORN n LOW VOLTAGE TO HORN - SHOULD BE WITHIN 0.5 VOLTS OF BATTERY n USE JUMPER WIRE TO TEST n CHECK GROUND INTEGRITY

12. HORN ALWAYS BLOWS n USUALLY CAUSED BY STICKING SWITCH CONTACTS OR RELAY n USE OHMMETER TO TEST FOR GROUNDED CIRCUIT n USE OHMMETER TO TEST RELAY (OR USE VOLTAGE DROP METHOD)

13. HAVE A NICE DAY! RUFUS’S HORN REPAIR WE DO IT RIGHT!