Grain Tank Light Testing (A.40.A.38 - G.40.A.20) - New Holland CX720 Repair Manual

Grain tank light - Testing (A.40.A.38 - G.40.A.20)
NOTE: The batteries must be fully charged and all connections clean and tight. Use a multimeter (DVOM) or an
unpowered test light for these tests.
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.
Close Work Light Switch. Measure
for 12 volts at Grain Tank Relay (pin
5).
2 Measure for 12 volts at Grain Tank
Light connector X108 (pin A).
3 Disconnect the Grain Tank Light.
Measure the resistance on circuit
681 (BK) between Grain Tank Light
connector X108 (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 Grain
Tank Light bulb.
2 4/7/2006
A.40.A / 74
Other Result (Possible Cause)
Perform Lower Work Lights Relay
Test.
Open circuit 65 (PU) or 646 (PU) be-
tween Lower Work Lights Relay (pin
5) and Grain Tank Light connector
X108 (pin A).
Open in circuit 681 (BK) between
Grain Tank Light connector X108
(pin B) and ground.