New Holland CX720 Repair Manual page 1305

Fuse and relay box - Problem solving (A.30.A.80 - G.40.A.30)
OPERATION
Power distribution consists of the following:
1. Unswitched battery power is available at all times. The battery positive terminal is connected to the unswitched
power bus from which all unswitched power circuits are energized.
Power is available to all of the following fuses 1, 2, 3, 4, 5, 16, 17, 18, 19, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32,
33, 34, 35, 38, 39, 40, 41, 42, 50, 51, 52, 53, 54, 55 and 56 regardless of the Ignition Switch position.
2. Switched battery power is supplied to the system when the Ignition System is ON. This switching is controlled by
Accessory 2 Relay, Accessory 3 Relay, Cab Work Lts Relay, CCM-1 Power Relay, CCM-2 Power Relay and CCM-3
Cab Power Relay.
When the ignition is switched ON, the Cab Power Relay is energized, supplying battery power to fuses 47, 48, 49.
Additionally the Accessory 2 Relay, Accessory 3 Relay, Cab Work Lts Relay, CCM-1 Power Relay and CCM-2 Power
Relay are energized and power is distributed to fuses 6, 7, 8, 9, 10, 11, 12, 13, 14, 36, 37, 43, 44, 45 and 46.
TROUBLESHOOTING
Before troubleshooting the power distribution system make sure that the following operating conditions are met:
A. The batteries are fully charged and all connections are clean and tight.
B. The transmission is in neutral or park.
C. Check all connectors for full installation, loose, corroded or pushed out terminals.
D. Determine if the power source being investigated is switched or unswitched.
E. If the power source problem is a switched power source, the relay controlling the circuit needs to be determined
and tested.
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
Problem
No power at one fuse.
No power at switched
fuses 47, 48, 49.
No power at switched
fuses 36, 37, 43, 44, 45, 46.
No power at switched
fuses 8, 9, 10, 11, 12, 13.
DISTRIBUTION SYSTEMS - ELECTRICAL POWER SYSTEM
Possible Cause
Power supply to fuse
CCM-3 Cab Power Relay
CCM-2 Power Relay
CCM-1 Power Relay
Accessory 3 Relay
Accessory 2 Relay
CAUTION
CAUTION
Go to fuse/circuit chart to determine power
supply circuit.
A - CCM-3 Cab Power Relay Test.Fuse
and relay box CCM3 relay - Testing
(A.50.A.80.73 - G.40.A.20).
B - CCM-2 Power Relay Test.Fuse
and relay box CCM2 relay - Testing
(A.50.A.80.72 - G.40.A.20).
C - CCM-1 Power Relay TestFuse
and relay box CCM1 relay - Testing
(A.50.A.80.71 - G.40.A.20).
D - Accessory 3 Relay TestFuse and
relay box Auxilary relay - Testing
(A.50.A.80.61 - G.40.A.20).
E - Accessory 2 Relay TestFuse and
relay box Auxilary relay - Testing
(A.50.A.80.61 - G.40.A.20).
2 4/7/2006
A.30.A / 1125
Correction