E0296-04-Ccm3 Keyswitch Voltage Shorted To Low Source (A.50.A.91.83 - G.30.B.53) - New Holland CX720 Repair Manual

E0296-04-CCM3 Keyswitch Voltage Shorted to Low Source
(A.50.A.91.83 - G.30.B.53)
E0296-04 - CCM3 Keyswitch Voltage Shorted to Low Source
Cause:
The CCM3 Keyswitch Voltage circuit is shorted to a lower than normal source.
Possible failure modes:
1. Loose or corroded connections, or damaged wires.
2. Batteries are discharged, and/or alternator/regulator failure.
3. The keyswitch voltage circuit to the CCM3 controller is shorted to ground.
NOTE : Check fuse F-38. If a short to ground occurred on this circuit the fuse will have blown.
4. Controller internal failure (internal regulator failure).
Solution:
1. Key switch voltage is used to initialize (wake-up) the module, and also supplies power to the 5 - 8 V regulators
for the regulated voltage circuits. The module will shutdown If the voltage is less than 9 volts, but there is no
shutdown for excessive voltage.
Key switch in "Off" position. Check fuse F-38.
A. If fuse F-38 is OK, continue with step 6.
B. If the fuse is blown, go to step 2.
2. Replace the failed fuse F-38.
A. If the fuse is OK, continue with step 3.
B. If the fuse immediately fails again, a short to ground exists in wire 053 red between the fuse and the key
switch in the cab main (CM) harness. Visually inspect the cab main harness for damage, bent or dislocated
pins, corroded terminals or broken wires. Locate short and repair.
3. If the fuse does not fail when it is replaced, turn the key switch to the "Acc" position.
A. If the fuse is okay, continue with step 4.
B. If the fuse immediately fails, there is a short to ground in one of the following wires:
wire 123 orange, key switch to the Wiper relay K-06
wire 241 orange, Wiper relay K-06 to Accessory 1 relay K-08
wire 126 orange, Accessory 1 relay K-08 to Accessory 2 relay K-03
All three wires are in the cab main harness. Visually inspect the cab main harness for damage, bent or
dislocated pins, corroded terminals or broken wires. Locate short and repair.
4. If the fuse does not fail with the key switch in the "Acc" position, turn the key switch to the "On" position.
A. If the fuse is okay, continue with step 5.
B. If the fuse immediately fails, there is a short to ground in one of the following wires:
wire 096 orange, key switch S-02 to CM harness splice
wire 100 orange, harness splice to CCM2 connector X015, pin J1-4
wire 099 orange, harness splice to CCM1 connector X018, pin J1-4
wire 101 orange, harness splice to CCM3 connector X012, pin J1-4
wire 097 orange, harness splice to InfoView connector X0644, pin C
wire 055 orange, harness splice to road light switch connector X256, pin 6
wire 095 orange, harness splice to power relays K-24, K-25 & K-26, pins 1
wire 222 orange, power relay K-26 to time delay module K-20, pin 30
wire 970 orange, time delay module K-20, pin 30 to fuel pump relay K-07, pin 1
DISTRIBUTION SYSTEMS - ELECTRONIC SYSTEM
A.50.A / 122
2 4/7/2006