Jacobsen AR3, Technical/Repair Manual

Page: 113 / 342

4-56 4181384 First Edition
ELECTRICAL
4
Mow Circuit
Symptom: Mow solenoid does not energize.
Backlap Circuit–Model TR-3
Symptom: Mow solenoid does not energize.
Probable Cause Remedy
Raise/lower switch was not momentarily
placed in the lower position. Momentarily place the raise/lower switch in the lower position to activate the cutting units.
Faulty mow switch. Test switch. (See “Rocker Switch Test” on page 4-66.)
Faulty mow solenoid. Test solenoid. (See “Solenoid Test” on page 4-68.)
Faulty mow switch 5V power supply circuit. Measure voltage between mow switch terminal 2 and ground. Voltage must be
approximately 5 VDC.
Faulty 5V mow switch input circuit. With the mow switch in the mow position, measure voltage between control module 5V
mow switch input terminal and ground. Voltage must be approximately 5 VDC.
Faulty 12V mow solenoid output circuit. With the mow switch in the mow position, measure voltage between control module 12V
mow solenoid output terminal and ground.
Measure voltage between mow solenoid yel/pnk wire terminal and ground.
Voltage must be approximately 12 VDC.
Open mow solenoid ground circuit. Check continuity between mow solenoid blk wire terminal and ground. Continuity must be
indicated.
Probable Cause Remedy
Raise/lower switch was not momentarily
placed in the lower position. Momentarily place the raise/lower switch in the lower position to activate the cutting units.
Faulty mow switch. Test switch. (See “Rocker Switch Test” on page 4-66.)
Faulty backlap switch. Test switch. (See “Backlap Switch Test” on page 4-69.)
Faulty mow solenoid. Test solenoid. (See “Solenoid Test” on page 4-68.)
Faulty mow switch 5V power supply circuit. Measure voltage between mow switch terminal 2 and ground. Voltage must be
approximately 5 VDC.
Faulty 5V mow switch input circuit. With the mow switch in the mow position, measure voltage between control module 5V
mow switch input terminal and ground. Voltage must be approximately 5 VDC.
Faulty 12V mow solenoid output circuit. With the mow switch in the mow position, measure voltage between control module 12V
mow solenoid output terminal and ground.
Measure voltage between mow solenoid yel/pnk wire terminal and ground.
Voltage must be approximately 12 VDC.
Open mow solenoid ground circuit. Check continuity between mow solenoid blk wire terminal and ground. Continuity must be
indicated.
Faulty 12V backlap switch input circuit. With the backlap lever in the backlap position, measure voltage between control module
12V backlap input terminal and ground. Voltage must be approximately 12 VDC.