New Holland CX720 Repair Manual page 1463

Audio system Antenna - Testing (A.50.A.87.80 - G.40.A.20)
NOTE: The batteries must be fully charged and all connections clean and tight. Use a multimeter (DVOM) for these
tests. For battery testing and service, see the battery section in the service manual.
DO NOT use a self-powered test light for any of these tests. Use of a self-powered light can cause damage
to components in this system. M979
Before performing any of the electrical tests, be sure all operating controls are in neutral or park lock position.
This will eliminate accidental movement of the machine or start-up of power driven equipment. M980
N° Test Point
1 Disconnect Antenna from Radio.
Measure resistance between center
terminal of Antenna (radio end) and
Antenna Mast.
2 Measure resistance from Antenna
ground wire to chassis ground.
Audio system Speaker - Testing (A.50.A.87.84 - G.40.A.20)
NOTE: The batteries must be fully charged and all connections clean and tight. Use a multimeter (DVOM) for these
tests. For battery testing and service, see the battery section in the service manual.
DO NOT use a self-powered test light for any of these tests. Use of a self-powered light can cause damage
to components in this system. M979
Before performing any of the electrical tests, be sure all operating controls are in neutral or park lock position.
This will eliminate accidental movement of the machine or start-up of power driven equipment. M980
N° Test Point
1 Disconnect connector from the Ra-
dio and Left Front Speaker.
Measure resistance between Ra-
dio connector C000 (pin 6) and Left
Front Speaker (pin B).
2 Measure resistance between Left
Front Speaker (pin A) and Radio
connector C000 (pin 8).
3 Disconnect connector from the Ra-
dio and Right Front Speaker.
Measure resistance between Radio
connector C000 (pin 4) and Right
Front Speaker connector X000 (pin
B).
DISTRIBUTION SYSTEMS - ELECTRONIC SYSTEM
CAUTION
WARNING
Expected Result
Less than 1 ohm.
If good reading, go to next test point.
Less than 1 ohm.
Antenna is good.
CAUTION
WARNING
Expected Result
Less than 1 ohm.
If good reading, continue with next
step.
Less than 1 ohm.
If good reading, left front speaker
wiring is okay.
Less than 1 ohm.
If good reading, continue with next
test point.
A.50.A / 69
2 4/7/2006
Other Result (Possible Cause)
Antenna.
Open circuit between Antenna and
frame ground.
Other Result (Possible Cause)
Open/short to ground in circuit 977
(WH) between Left Front Speaker
(pin 6) and Radio connector C000
(pin B).
Open/short to ground in circuit 983
(BL) and 981 (BL) or 982 (BL) be-
tween Left Front Speaker (pin A) and
Radio connector C000 (pin 8) or Left
Rear Speaker (pin A).
Open/short to ground in circuit
976 (WH) between Radio connec-
tor C000 (pin 4) and Right Front
Speaker connector C000 (pin B).