New Holland CX720 Repair Manual page 1389

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.
Activate Unload Tube Light Relay.
Measure for 12 volts at Unload Tube
Relay (pin 5).
2 Measure for 12 volts at Unload Tube
Light connector X105 (pin A).
3 Disconnect the Unload Tube Light.
Measure the resistance on circuit
669 (BK) between Unload Tube
Light connector X105 (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, go to next test point.
Less Than 1 ohm.
If good reading, replace the Unload
Tube Light bulb.
2 4/7/2006
A.40.A / 73
Other Result (Possible Cause)
Perform Unload Tube Light Relay
Test.
Open circuit 77 (PU) between Un-
load Tube Relay (pin 5) and Unload
Tube Light connector X105 (pin A).
Open in circuit 669 (BK) between
Unload Tube Light connector X105
(pin B) and ground.