New Holland CX720 Repair Manual page 1355

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 Place Ignition Switch in "ON" posi-
tion.
Measure for 12 volts at Beacon
Light Switch connector X130 (pin 2).
2 Close Beacon Light Switch.
Measure for 12 volts at Beacon
Light Switch connector X130 (pin 3).
Beacon Electrical light - Testing (A.40.A.15.85 - G.40.A.20)
N° Test Point
1 Place Ignition Switch in "ON" posi-
tion. Close Beacon Light Switch.
Measure for 12 volts at Beacon
Light Relay (pin 5).
2 Measure the voltage at Rear Beacon
Light connector X247 (pin A).
3 Disconnect the Rear Beacon. Mea-
sure the resistance on circuit 623
(BK) between Rear Beacon Light
connector X247 (pin B) and ground.
Beacon Electrical light - Testing (A.40.A.15.85 - G.40.A.20)
N° Test Point
1 Place Ignition Switch in "ON" posi-
tion. Close Beacon Light Switch.
Measure for 12 volts at Beacon
Light Relay (pin 5).
2 Measure for 12 volts at LH Front
Beacon Light connector X113 (pin
A).
3 Disconnect the LH Front Beacon.
Measure the resistance on circuit
666(BK) between LH Front Beacon
Light connector X113 (pin B) and
ground.
DISTRIBUTION SYSTEMS - LIGHTING SYSTEM
CAUTION
WARNING
Expected Result
12 volts.
If good reading, go to next test point.
12 volts.
If good reading, system OK.
Expected Result
12 volts.
If good reading, go to next test point.
12 volts.
If good reading, go to next test point.
Less than 1 ohm.
If good reading, replace the Beacon
Light bulb of the Rear Beacon.
Expected Result
12 volts.
If good reading, go to next test point.
12 volts.
If good reading, go to next test point.
Less than 1 ohm.
If good reading, replace the Beacon
Light bulb of the LH Front Beacon.
2 4/7/2006
A.40.A / 39
Other Result (Possible Cause)
Open circuit 172 (OR) or 45 (OR) be-
tween Beacon Light Switch connec-
tor X130 (pin 2) and Fuse #49.
Beacon Light Switch.
Short to ground on circuit 166 (YE)
between Beacon Light Switch con-
nector X130 (pin 3) and CCM-2 (pin
J1-2)
A short to ground will blow Fuse #49.
Other Result (Possible Cause)
Perform Beacon Light Relay Test.
Open circuit 578 (PU) between Bea-
con Light Relay (pin 5) and Rear
Beacon Light connector X247 (pin
A).
Open circuit 623 (BK) between Rear
Beacon Light connector X247 (pin B)
and ground.
Other Result (Possible Cause)
Perform Beacon Light Relay Test.
Open in circuit 579 (PU) or 663 (PU)
between Beacon Light Relay (pin 5)
and LH Front Beacon Light connec-
tor X113 (pin A).
Open in circuit 666 (BK) between LH
Front Beacon Light connector X113
(pin B) and ground.