
126 RENR9348-01
Troubleshooting Section
Repair: There is an open circuit in the harness or
in a connector b
etween the batteries and the ECM
relay. Ensure that the circuit breaker for the ECM
relay has not tripped. Repair the wiring and/or the
connectors. R
eplace parts, if necessary. Verify that
the original problem has been resolved.
STOP.
Test Step 6. Check the Voltage for the
Relay C ontrol at the ECM Relay
A. Check that the battery disconnect switch is in the
ON position. Ensure that the emergency stop
switch is in
the RUN position.
B. Measure the voltage between terminals 2 (relay
ground) and
5 (relay control) at the connector for
the ECM relay.
Acorrectme
asurement will indicate that no
voltage is present between the terminals.
C. Place the em
ergencystopswitchintheSTOP
position.
D. Again, mea
sure the voltage between terminals
2 (relay ground) and 5 (relay control) at the
connector for the ECM relay.
A correct measurement will indicate that the
voltage is 24 ± 3 VDC between the terminals.
Expected Result:
The voltag
e is correct between connector terminals
for each position of the emergency stop switch.
Results:
•
OK – The voltage is correct for each position of
the emerg
ency stop switch. The circuit for the relay
control is operating correctly. The problem may
be the ECM relay or the problem may be in the
ground ci
rcuit from the batteries to the ECM. Leave
the connector for the ECM relay disconnected.
Proceed to Test Step 7.
•
Not OK – One of the following conditions exists:
Voltage is present at the terminals with the
emergen
cy stop switch in the RUN position.
Voltage is not present at the terminals with the
emergency stop switch in the STOP position.
Repair: There is a problem in the circuit for the
emergency stop switch. Repair the circuit and
retest
the electrical power supply circuit. Refer
to the diagnostic functional test Troubleshooting,
“Emergency Stop Circuit - Test”.
STOP.
Test Step 7. Test the Ground Circuit
A. Ensure that the battery disconnect switch is in the
ON position.
B. Measure the voltage between the battery’s
+Battery terminal and the following test points. If
voltage is not
present at a test point, the problem
is in the wire or in the connector that precedes the
point in the circuit. Refer to Illustration 47 as a
reference.
Table 21
Device Test location
Input termina
l
Battery disconnect switch
Output terminal
Starting motor
−Battery terminal
Term ina l 6 1
Term ina l 6 3
Term ina l 6 5
Term ina l 6 7
P1 EC M connector
Term ina l 6 9
Connector for the ECM
relay
Terminal 2
Expected Result:
A voltage of 24 VDC is measured between the
+Battery and each test location in Table 21.
Results:
•
OK – A voltage of 24 VDC is measured for each
test location.
Repair: The wiring for the ground circuit is OK.
The problem is an open circuit in the ECM relay.
Replace the ECM relay. Verify that the original
problem has been resolved.
STOP.
•
Not OK – A voltage of 24 VDC is not present at
one of the test locations.
Repair: There is an open circuit in the harness or
in the connector that precedes this test location.
Repair the wiring and/or the connectors. Replace
parts, if necessary. Verify that the original problem
has been resolved.
STOP.