| Page 19 - Index - Page 21 |
Mercury
Alternator Driven Ignition Systems
Two Cylinder Engines
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- NOTE: These engines sometimes develop a problem where you only have one cylinder firing. This can be caused by the flywheel magnets coming loose and shifting around until they touch. If only one cylinder is firing, remove the flywheel and check the magnets to see if they are tightly bonded.
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1979-1997 models
(With 332-7452 Switch Box)
|
No Fire At All:
- Disconnect the Black/Yellow kill wire and retest. If the ignition system now fires, the kill circuit has a problem.
- Check the stator resistance and DVA output:
|
| |
Wire |
Read To |
Resistance |
DVA |
|
| |
Black/Yellow
Black/White |
Engine GND
Engine GND |
3250-3650
200-250 |
180V or more
25V or more |
|
- Check the trigger resistance and output:
|
| |
Wire |
Read To |
Resistance |
DVA |
|
| |
Brown/Yellow
Brown/Yellow
Brown/White |
Brown/White
Engine GND
Engine GND |
750-1400
Open
Open |
4V or more
1V or more
1V or more |
|
No Fire on One Cylinder:
- Check the DVA output on the green wires from the switch box while connected to the ignition coils. Check the reading on the switch box terminal AND on the ignition coil terminal. You should have a reading of at least 150V or more at both places. If the reading is low on one cylinder, disconnect the green wire from the ignition coil for that cylinder and reconnect it to a load resistor. Retest. If the reading is now good, the ignition coil is likely bad. A continued low reading indicates a bad power pack.
|
1994-1998 models
(With the 18495 Switch Box)
|
No Fire At All:
- Disconnect the Black/Yellow kill wire and retest. If the ignition system now fires, the kill circuit has a problem.
- Check the stator resistance and DVA output:
|
| |
Wire |
Read To |
Resistance |
DVA |
|
| |
Blue
Red |
Black
Black |
3250-3650
200-250 |
180V or more
25V or more |
|
- NOTE: This system uses a timing advance circuit inside the switch box to control timing. The black stator wire is NOT tied directly to ground inside the pack.
- Check the trigger resistance and output:
|
| |
Wire |
Read To |
Resistance |
DVA |
|
| |
Brown/Yellow
Brown/Yellow
Brown/White |
Brown/White
Engine GND
Engine GND |
750-1400
Open
Open |
4V or more
1V or more
1V or more |
|
No Fire on One Cylinder:
- Check the DVA output on the green wires from the switch box while connected to the ignition coils. Check the reading on the switch box terminal AND on the ignition coil terminal. You should have a reading of at least 150V or more at both places. If the reading is low on one cylinder, disconnect the green wire from the ignition coil for that cylinder and reconnect it to a load resistor. Retest. If the reading is now good, the ignition coil is likely bad. A continued low reading indicates a bad power pack.
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| Page 19 - Index - Page 21 |
