Evinrude & Johnson E75DPLSCB, Руководство по обслуживанию, Страница: 115 / 349

113
SYSTEM ANALYSIS
IGNITION OUTPUT TESTS
6
Ignition Control Circuit Tests
Use a digital multimeter to test the following:
•
System voltage supply to ignition coil.
•
Ignition control signal from EMM .
•
Engine harness resistance.
Disconnect ignition coil connector.
Supply voltage test:
Connect the red meter lead to pin 3 (white/red) of
the engine harness connector and the black lead
to ground. With KEY ON, voltage should be
approximately 1 V less than battery voltage.
Control signal test:
Set meter to the Hz scale to check ignition control
signal.
Connect the red meter lead to pin 2 (orange) of
the engine harness connector and the black lead
to ground. Activate diagnostics software
Static
Ignition test and observe meter for consistent
reading (approximately 2 Hz).
If control signal is present, connect black meter
lead to pin 1 and repeat test to confirm harness
ground.
Harness resistance test:
If control signal is NOT present, calibrate multime-
ter to low ohms scale.
With key switch OFF, remove the EMM J1-B con-
nector and test the continuity of each ignition con-
trol circuit (orange). Check resistance between J1-
B connector and ignition coil connector. Refer to
engine wiring diagram.
If circuits test good, replace EMM .
Ignition Coil Tests
There are no simple ignition coil tests available.
Before replacing an ignition coil, be sure:
•
55 V is supplied to the white/red wire of the igni-
tion coil connector
•
A control signal is present on the orange wire of
the ignition coil connector. Refer to
Ignition
Control Circuit Tests
on p. 113.
•
The black wire of the ignition coil connector pro-
vides continuity to ground.
•
The secondary spark plug lead provides conti-
nuity.
If all of the above tests are good, and a cylinder
does not have spark, replace the ignition coil with
a known good coil.
Capacitor Test
IMPORTANT:
Make sure the capacitor is dis-
charged before testing. Make a momentary con-
nection between the two terminals to ground any
stored energy.
Use an ohmmeter set on the high ohms scale to
test the capacitor. Connect the meter leads to the
capacitor terminals:
•
If the capacitor is working correctly, it will store
energy from the meter. The resistance reading
will increase until it goes to (nearly) infinity.
•
If the capacitor is shorted, the reading will
immediately show full continuity.
•
If there is an open circuit in the capacitor, the
meter will show no continuity.
If the resistance reading starts as a negative num-
ber, or the reading goes down in value, the capac-
itor already retains some stored energy. Ground
the capacitor and test again.
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