Header Work Light Relay - Testing (A.40.A.39.82 - G.40.A.20) - New Holland CX720 Repair Manual

Header work light Relay - Testing (A.40.A.39.82 - 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 Header
Work Lights Relay (pin 5).
2 Measure for 12 volts at Header
Work Lights Relay (pin 1).
3 Measure for 12 volts at Header
Work Lights Relay (pin 3).
4 Disconnect the Header Work Lights
Relay. Measure resistance on cir-
cuit 238 (BK) between Header Work
Lights Relay (pin 2) and ground.
Header work light Electrical light - Testing (A.40.A.39.85 - G.40.A.20)
Test Point
N°
1 Place Ignition Switch in "ON" posi-
tion.
Close Work light Switch, measure for
12 volts at Header Work Lights Re-
lay (pin 5).
2 Measure for 12 volts at LH Header
Light connector X162 (pin A).
3 Disconnect the LH Header Light.
Measure the resistance on circuit
267(BK) between LH Header Light
connector X162 (pin B) and ground.
DISTRIBUTION SYSTEMS - LIGHTING SYSTEM
CAUTION
WARNING
Expected Result
12 volts.
If good reading, the relay is operating
properly.
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 Header
Work Lights Relay.
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 LH
Header Light bulb.
2 4/7/2006
A.40.A / 75
Other Result (Possible Cause)
Header Work Lights Relay Test.
Adjacent circuits.
Go to next test point.
Open or short on circuit 188 (PU),
189 (PU) or 190 (PU) between
Header Work Lights Relay (pin 1)
and CCM-1
(pin J1-11).
See Service Manual for testing of
CCM.
Open in circuit 62 (RD) between
Header Work Lights Relay (pin 3)
and Fuse #30. Short to ground in
circuit 63 (PU), 258 (PU) or 257 (PU)
between Header Work Lights Relay
(pin 5) and Header lights connectors
X167 and X168 (pin A).
A short will cause Fuse #30 to blow.
Open circuit 238 (BK) between
Header Work Lights Relay (pin 2)
and ground.
Other Result (Possible Cause)
Perform Header Work Lights Relay
Test.
Open circuit 63 (PU) or 257 (PU)
between Header Lights Relay (pin
5) and LH Header Light connector
X162 (pin A).
Open circuit 267 (BK) between LH
Header Light connector X162 (pin B)
and ground.