Textron JACOBSEN R-311 69166, Technical/Repair Manual

Page: 123 / 402

4-72 4203781 First Edition
ELECTRICAL
4
Horn and Audible Alert Circuit
Symptom: Horn does not sound when horn switch is pressed.
Symptom: Horn does not sound when engine coolant temp light turns on.
Symptom: Horn does not sound when hyd oil temp light turns on.
Probable Cause Remedy
Faulty horn switch. With the key switch in the run position, press the horn switch. If the horn does not sound,
test horn switch.
Faulty horn. Connect a test light between horn terminals (pnk/blk and blk wires). With the key switch in
the run position, press the horn switch. If the test light turns on and the horn does not
sound, replace the horn.
Faulty horn relay. Test horn relay. (See “Relays Test” on page 4-75.)
Faulty ground circuit. Check continuity between horn blk wire terminal and ground. Continuity must be
indicated.
Probable Cause Remedy
Faulty diode. Test diode (V2). (See “Diodes Test” on page 4-85.)
Probable Cause Remedy
Faulty diode. Test diode (V6).(See “Diodes Test” on page 4-85.)