
RENR9348-01 125
Troubleshooting Section
•
Not OK – The voltage is not correct at the ECM.
There is a probl
em with the electrical power
supply circuit. Leave the J1/P1 ECM connectors
disconnected. Proceed to Test Step 3.
Test Step 3. Check the Batteries
A. Measure the no
-load battery voltage at the battery
posts.
The correct vo
ltage is between 22.0 VDC and
27.0 VDC.
B. Load test the
batteries. Use the 4C-4911
Battery Load Tester. Refer to the Operating
Manual, SEHS9249. Refer to Special Instruction,
SEHS7633 for
details.
Expected Result:
The batteries pass the load test.
Results:
•
OK – The batteries pass the load test. There is a
problem in t
he harness between the batteries and
the ECM. There may be a problem in the circuit for
the ECM relay. Proceed to Test Step 6.
•
Not OK – The batteries failed the load test.
Repair: The
batteries are the cause of the
original problem. There may be a problem with
the alternator. Recharge the batteries or replace
the batteri
es.Restorethewiringtotheoriginal
configuration.
If a proble
m with the alternator is suspected, refer
to Troubleshooting, “Alternator”.
STOP.
Test Step 4. Check the Voltage from the
ECM Relay to the ECM
A. Turn the battery disconnect switch to the OFF
position.
B. Disconnect the connector from the ECM relay.
C. Remove th
ewirefromtheterminallocation3of
the connector for the ECM relay.
D. Fabricat
e a jumper wire that is long enough to
provide a test circuit for a terminal location at the
ECM relay. Crimp a spade terminal to one end of
the jump
er wire.
E. Install the jumper wire into terminal location 3 of
the conn
ector for the ECM relay. Connect the
connector to the ECM relay.
F. Turn the battery disconnect switch to the ON
position. Ensu
re that the emergency stop switch
is in the RUN position.
G. Measure the vo
ltage between the loose end of the
jumper wire and engine ground.
H. Turn the batte
ry disconnect switch to the OFF
position.
Expected Resu
lt:
Voltage is present on terminal 3 at the ECM relay.
Results:
•
OK – Voltage is
present on terminal 3 at the ECM
relay.
Repair: If vol
tage is present on terminal 3, there
is a problem in the harness between the ECM
relay and the ECM. Repair the harness and/or the
connectors.
Replace parts, if necessary.
STOP.
•
Not OK – Voltage is not present on terminal 3 at
the ECM relay. There is a problem in the harness
between the
ECM relay and the batteries. There
may be a problem with the relay. Proceed to Test
Step 6.
Test Step 5. Check for +Battery Voltage at
the ECM Relay
A. Disconnec
t the connector from the ECM relay.
B. Turn the battery disconnect switch to th e ON
position.
C. Measure the voltage between terminal 1 at the
connector
for the ECM relay and the engine
ground stud.
Expected R
esult:
The measured voltage is 24 ± 3 VDC.
Results:
•
OK – The vo
ltage is 24 ± 3 VDC. The proper
voltage is reaching terminal 1 of the ECM relay.
Check the circuit for the relay control for the proper
operatio
n. Leave the connector for the ECM relay
disconnected. Proceed to Test Step 7.
•
Not OK – Th
evoltageisnot24±3VDC.