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Typical Mercury Ignition systems
Mercury
Battery CD Ignitions without Points
Three Cylinder Engines
332-4796/393-4797 Type Ignitions
•SERVICE NOTE: Check the battery voltage at approximately 3500 RPM, MAXIMUM allowable reading is 16 volts and minimum is 12V. Running below 12V or over 16 volts will damage the ignition. Check for loose connections or a bad battery. Maintenance free batteries are NOT recommended for this application.
General:
1. Clean all battery connections and engine grounds.
2. Disconnect the mercury tilt switch and retest. If the ignition works properly, replace the mercury switch.
3. Connect a spark gap tester to the spark plug wires and check for fire on all cylinders. If some cylinders fire and not others, the problem is likely in the distributor cap, rotor button or spark plug wires.
4. Perform a voltage drop test after the engine is repaired to see if there is a problem with the voltage going to the CD module. At cranking and while the engine is running, use a DC voltmeter and put the black meter lead on the battery POS (+) post and the red meter lead on the positive battery cable at the starter solenoid. Keep the black lead on the battery post and shift the red meter lead to the positive post of the rectifier, then to the red and white terminals on the switch box. If you find a reading above 0.6V, there is a problem at the point where the voltage jumped up. For instance, if the meter reads 0.4V until you get to the white terminal and then jumps to 2.3V on the white terminal –this indicates a problem in the keyswitch, or harness. Repeat the test for the negative battery post by putting the black meter lead on the battery NEG (-) post and the red meter lead on the negative battery cable terminal, then shifting to the engine block, rectifier base and case ground of the CD module.
No fire at all:
1. Connect a spark gap tester to the high-tension lead coming from the ignition coil and set it to approximately 7/16". When you crank the engine over, if it fires while the spark gap tester is connected to the coil and does not fire through the spark plug wires - there is a problem in the distributor cap, rotor button or spark plug wires.
2. Check the DC voltage present on the white and red terminals while at cranking. It MUST be at least 9˝ volts. If not, there is a problem in the harness, key switch, starter battery cables or battery.
3. Check the DC voltage on the white/black trigger terminal at cranking, there must be at least 9V available with the trigger wire connected.
4. Check DVA voltage between the blue and black trigger wires (They must be connected to the switch box). You should read at least 3V. A low reading indicates a bad trigger.
5. Check DVA voltage on the green wire going to the coil, it should be over 100 volts at cranking.
Only fires when you let off of the keyswitch:
1. This symptom usually indicates a bad trigger or low voltage.
No fire or intermittent on one cylinder:
1. Connect a spark gap tester to the high-tension leads coming from the distributor cap and set the gap to approximately 7/16".
2. Align the rotor with #1 spark plug wire. Disconnect the trigger wires and connect a jumper wire from the white/black trigger terminal to the black trigger terminal on the switch box.
3. Connect another jumper wire to the blue trigger terminal turn the ignition switch on. Strike the jumper wire from the blue terminal against engine ground
– (DO NO HOLD THE JUMPER AGAINST ENGINE GROUND!). (Or use a CD Tester). Only the #1 spark plug wire should fire. If another spark plug wire fires, there is a problem in the distributor cap.
4. Repeat the test for the other cylinders.
High speed miss:
•Check the battery voltage on the red and white terminals of the switch box at high speed, the voltage should be between 12.5V and 16V DC. A reading outside this range will damage the CD module. If the readings are abnormal, perform the voltage drop test described above.
Mercury
Battery CD Ignitions without Points
Four and Six Cylinder Engines
332-2986/393-3736 Type Ignitions
•SERVICE NOTE: Check the battery voltage at approximately 3500 RPM, MAXIMUM allowable reading is 16 volts and minimum is 12V. Running below 12V or over 16 volts will damage the ignition. Check for loose connections or a bad battery. Maintenance free batteries are NOT recommended for this application.
General:
1. Clean all battery connections and engine grounds.
2. Disconnect the mercury tilt switch and retest. If the ignition works properly, replace the mercury switch.
3. Connect a spark gap tester to the spark plug wires and check for fire on all cylinders. If some cylinders fire and not others, the problem is likely in the distributor cap, rotor button or spark plug wires.
4. Perform a voltage drop test after the engine is repaired to see if there is a problem with the voltage going to the CD module. At cranking and while the engine is running, use a DC voltmeter and put the black meter lead on the battery POS (+) post and the red meter lead on the positive battery cable at the starter solenoid. Keep the black lead on the battery post and shift the red meter lead to the positive post of the rectifier, then to the red and white terminals on the switch box. If you find a reading above 0.6V, there is a problem at the point where the voltage jumped up. For instance, if the meter reads 0.4V until you get to the white terminal and then jumps to 2.3V on the white terminal –this indicates a problem in the keyswitch, or harness. Repeat the test for the negative battery post by putting the black meter lead on the battery NEG (-) post and the red meter lead on the negative battery cable terminal, then shifting to the engine block, rectifier base and case ground of the CD module.
No fire at all:
1. Connect a spark gap tester to the high-tension lead coming from the ignition coil and set it to approximately 7/16". When you crank the engine over, if it fires while the spark gap tester is connected to the coil and does not fire through the spark plug wires - there is a problem in the distributor cap, rotor button or spark plug wires.
2. Check the DC voltage present on the white and red terminals while at cranking. It MUST be at least 9˝ volts. If not, there is a problem in the harness, key switch, starter battery cables or battery.
3. Check the DC voltage on the white/black trigger terminal at cranking, there must be at least 9V available with the trigger wire connected.
4. Check DVA voltage between the blue and black trigger wires (They must be connected to the switch box). You should read at least 3V. A low reading indicates a bad trigger.
5. Check DVA voltage on the green wire going to the coil, it should be over 100 volts at cranking.
Only fires when you let off of the keyswitch:
1. This symptom usually indicates a bad trigger or low voltage.
No fire or intermittent on one cylinder:
1. Connect a spark gap tester to the high-tension leads coming from the distributor cap and set the gap to approximately 7/16".
2. Align the rotor with #1 spark plug wire. Disconnect the trigger wires and connect a jumper wire from the white/black trigger terminal to the black trigger terminal on the switch box.
3. Connect another jumper wire to the blue trigger terminal turn the ignition switch on. Strike the jumper wire from the blue terminal against engine ground – (DO NO HOLD THE JUMPER AGAINST ENGINE GROUND!). (Or use a CD Tester). Only the #1 spark plug wire should fire. If another spark plug wire fires, there is a problem in the distributor cap.
4. Repeat the test for the other cylinders.
High speed miss:
1. Check the battery voltage on the red and white terminals of the switch box at high speed, the voltage should be between 12.5V and 16V DC. A reading outside this range will damage the CD module. If the readings are abnormal, perform the voltage drop test described above.
2. Perform a high-speed shutdown and read the spark plugs. Check for water. A crack in the block can cause a high speed miss when the water pressure gets high, but a normal shutdown will mask the problem.
Mercury Alternator Driven Ignition Systems
Two Cylinder Engines
•SERVICE 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.
1979-1997 models
(With 332-7452 Switch Box)
No fire at all:
1. Disconnect the Black/Yellow kill wire and retest. If the ignition system now fires, the kill circuit has a problem.
2. 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
3. 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:
1. 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:
1. Disconnect the Black/Yellow kill wire and retest. If the ignition system now fires, the kill circuit has a problem.
2. 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
•SERVICE 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.
3. 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:
1. Disconnect the Black/Yellow kill wire and retest. If the ignition system now fires, the kill circuit has a problem.
2. 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
•SERVICE 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.
3. 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.
Two Cylinder Engines
1996-2000
Two Cylinder Engines Using a Combination Switch Box and Ignition Coil (CDM Modules)
No Fire At All:
1. Disconnect the black/yellow kill wires from the harness and retest. If the engine’s ignition fires now, the kill circuit has a fault-possibly the keyswitch, harness or shift switch.
2. Swap the White/Green and Green/White stator wire and retest. If the problem moves to the other cylinder, the stator is likely bad.
3. Disconnect one CDM module at a time and using a set of piercing probes and jumper wires- short the stator and trigger wires to engine ground.
Retest. If the other module start firing, the one you unplugged is bad.
4. Disconnect the yellow wires from the stator to the rectifier and retest. If the engine fires, replace the rectifier.
5. Check the cranking RPM. A cranking speed less than 250-RPM will not allow the system to fire properly.
6. Check the stator resistance and DVA output as given below:
Wire Read To Resistance DVA
White/Green Green/White 500-700 180V or more
No fire or Intermittent on One Cylinder:
1. If the cylinders are only acting up above an idle, connect an inductive Tachometer to all cylinders and try to isolate the problem cylinders.
2. Using a set of piercing probes, check the trigger DVA output as given below:
Wire Read To Resistance DVA
Brown wire
White wire
Brown wire White wire
Engine GND
Engine GND 800-1400
Open
Open 3V or more
1V or more
1V or more
3. If # 1 is not firing, swap the White/Green and Green White stator wire and retest. If the problem moves to the #2 cylinder, the stator is likely bad. If no change, swap locations with #21 and see if the problem moves. If it does, the module is bad. A continued no fire on the same cylinder indicates a bad trigger.
High Speed Miss:
1. Connect an inductive Tachometer to each cylinder in turn and try to isolate the problem. A high variance in RPM on one cylinder indicates a problem usually in the trigger or CDM module.
2. Perform a high-speed shutdown and read the spark plugs. Check for water. A crack in the block can cause a high speed miss when the water pressure gets high, but a normal shutdown will mask the problem.
3. Remove the flywheel and check the triggering and charge coil flywheel magnets for cracks or broken magnets.
Three Cylinder Engines
1976-1997
Engines Using a Single Switch Box and Three Ignition Coils
No Fire At All:
1. Disconnect the black/yellow kill wire AT THE PACK and retest. If the engine’s ignition fires now, the kill circuit has a fault-possibly the keyswitch, harness or shift switch.
2. Disconnect the yellow wires from the stator to the rectifier and retest. If the engine fires, replace the rectifier.
3. Check the cranking RPM. A cranking speed less than 250-RPM will not allow the system to fire properly.
4. Check the stator resistance and DVA output as given below:
Motors with Flex-plate Flywheel
Wire Read To Resistance DVA
Blue
Red
Engine Gnd
Engine Gnd 5800-7000
135-165 180V or more
25V or more
Motors with Cast, Vented Flywheel
Wire Read To Resistance DVA
Blue
Red
Engine Gnd
Engine Gnd 3250-3650
75-90 180V or more
25V or more
Motors with Red Stator
Wire Read To Resistance DVA
White/Green Green/White 500-700 180V or more
Red Stator Adapter
Wire Read To Resistance DVA
Blue Engine Ground Open 180V or more
Mercury Alternator Driven Ignition Systems
No fire or Intermittent on One or More Cylinders:
1. If the cylinders are only acting up above an idle, connect a inductive Tachometer to all cylinders and try to isolate the problem cylinders.
2. Check the trigger resistance and DVA output as given below:
Wire Read To Resistance DVA
Brown wire(#1)
White wire(#2)
Purple wire(#3)
Brown wire(#1)
White wire(#2)
Purple wire(#3) White/black
White/black
White/Black
Engine GND
Engine GND
Engine GND 800-1400
800-1400
800-1400
Open
Open
Open 4V or more connected
4V or more connected
4V or more connected
1V or more(a)
1V or more(a)
1V or more(a)
(a) This reading can be used to determine if a pack has a problem in the triggering circuit. For instance, if you have no fire on one cylinder and the DVA trigger reading for that cylinder is low – disconnect the trigger wire and recheck the DVA output to ground from the trigger wire. If the reading stays low – the trigger is bad.
3. 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.
Engine will not rev beyond 3000-4000 RPM:
1. Connect an inductive Tachometer to all cylinders and try to isolate the problem. A single cylinder dropping fire will likely be the switch box or ignition coil. All cylinders acting up usually indicate a bad stator.
2. Connect a DVA meter to the stator’s Blue wire and do a running test. The DVA voltage should jump up to well over 200V and stabilize. A drop in voltage right before the problem occurs indicates a bad stator. (Blue to Engine GND if the engine has a Red stator kit installed).
3. Connect a DVA meter to the Red wire. The DVA voltage should show a smooth climb in voltage and remain high through the RPM range. A reading lower than what is on the Blue wire indicates a bad stator.
No fire at all:
1. Connect an inductive Tachometer to all cylinders and try to isolate the problem. A high variance in RPM on one cylinder indicates a problem usually in the switch box or ignition coil. Occasionally a trigger will cause this same problem. Check the trigger as described above under “No fire or Intermittent on One or More Cylinders”.
2. Perform a high-speed shutdown and read the spark plugs. Check for water. A crack in the block can cause a high speed miss when the water pressure gets high, but a normal shutdown will mask the problem.
3. Remove the flywheel and check the triggering and charge coil flywheel magnets for cracks or broken magnets.
Three Cylinder Engines 1996-2000
Three Cylinder Engines Using a Combination Switch Box and Ignition Coil (CDM Modules)
No fire at all:
1. Disconnect the black/yellow kill wires from the harness and retest. If the engine’s ignition fires now, the kill circuit has a fault-possibly the keyswitch, harness or shift switch.
2. Disconnect one CDM module at a time and see if the other modules start firing. If they do, the module you just unplugged is bad.
3. Disconnect the yellow wires from the stator to the rectifier and retest. If the engine fires, replace the rectifier.
4. Check the cranking RPM. A cranking speed less than 250-RPM will not allow the system to fire properly.
5. Check the stator resistance and DVA output as given below:
Wire Read To Resistance DVA
White/Green White/Green 500-700
180V or more
No fire or Intermittent on One or More Cylinders:
1. If the cylinders are only acting up above an idle, connect a inductive Tachometer to all cylinders and try to isolate the problem cylinders.
2. Check the trigger resistance and DVA output as given below:
Wire Read To Resistance DVA
Purple wire
White wire
Brown wire Engine GND
Engine GND
Engine GND Open
Open
Open 3V or more
3V or more
3V or more
•SERVICE NOTE: These triggers have the bias circuitry built into them, therefore you cannot measure the resistance like you could the older engines. In addition, there are four triggering coils used.
3. If # 1 is not firing, disconnect #2 CDM module and see if the #1 module starts firing. If it does, the module you just unplugged is bad. If it does not, disconnect #3 CDM module and see if the #1 module starts firing. If it does, the module you just unplugged is bad.
4. If # 2 or #3 are not firing, swap locations with #1 and see if the problem moves. If it does, the module is bad. A continued no fire on the same cylinder indicates a bad trigger.
High speed miss:
1. Connect an inductive Tachometer to all cylinders and try to isolate the problem. A high variance in RPM on one cylinder indicates a problem usually in the trigger or CDM module.
2. Perform a high-speed shutdown and read the spark plugs. Check for water. A crack in the block can cause a high speed miss when the water pressure gets high, but a normal shutdown will mask the problem.
3. Remove the flywheel and check the triggering and charge coil flywheel magnets for cracks or broken magnets.
Four Cylinder Engines 1968
Engines with Ignition Driver Distributors
WARNING!! DO NOT CONNECT 12VDC TO THE IGNITION MODULE AS DC VOLTAGE WILL BURN OUT THE SWITCH BOX AND IGNITION DRIVER.
No fire at all::
1. Disconnect the orange kill wire AT THE PACK and retest. If the engine’s ignition fires now, the kill circuit has a fault-possibly the keyswitch, harness or Tilt sensor.
2. Check the Ignition Driver resistance and DVA output:
Wire Read To Resistance DVA
Red
Blue
Green White wire
White wire,
Engine GND 400
10
N/A 180V or more
20v or more
150v or more
3. Check the cranking RPM. A cranking speed of less than 250-RPM will not allow the system to fire properly.
No fire or Intermittent on One or More Cylinders:
1. If only one or two cylinders are not firing on this system, the problem is going to be either in the distributor cap or spark-plug wires.
Four Cylinder Engines 1978-1997
Four Cylinder Engines Using a Single Switch Box and Four Ignition Coils
No fire at all:
1. Disconnect the black/yellow kill wire AT THE PACK and retest. If the engine’s ignition fires now, the kill circuit has a fault-possibly the keyswitch, harness or shift switch.
2. Disconnect the yellow wires from the stator to the rectifier and retest. If the engine fires, replace the rectifier.
3. Check the cranking RPM. A cranking speed less than 250-RPM will not allow the system to fire properly.
4. Check the stator resistance and DVA output as given below:
Motors with Flex-plate Flywheel
Wire Read To Resistance DVA
Blue
Red/White
Blue/White
Engine Gnd 5000-7000
125-155 180V or more
25V or more
Motors with Cast, Vented Flywheel
Wire Read To Resistance DVA
Blue
Red
Blue/White
Red/White 3250-3650
75-90 180V or more
25V or more
Motors with Red Stator
Wire Read To Resistance DVA
White/Green Green/White 500-700 180V or more
Red Stator Adapter
Wire Read To Resistance DVA
Blue
Blue (each) Blue
Engine GND Open
Open 180V or more
180V or more
No fire or Intermittent on One or More Cylinders:
1. If the cylinders are only acting up above an idle, connect an inductive Tachometer to all cylinders and try to isolate the problem cylinders.
2. Check the trigger resistance and DVA output as given below:
Wire Read To Resistance DVA
Purple wire(#1)
Brown wire(#3)
Purple wire(#1)
White wire(#2)
Brown wire(#3)
White/Black wire(#4) White (#2)
White/black (#4)
Engine GND
Engine GND
Engine GND
Engine GND 800-1400
800-1400
Open
Open
Open
Open 4V or more connected
4V or more connected
1V or more(a)
1V or more(a)
1V or more(a)
1V or more(a)
(a) This reading can be used to determine if a pack has a problem in the triggering circuit. For instance, if you have no fire on one cylinder and the DVA trigger reading for that cylinder is low – disconnect the trigger wire and recheck the DVA output to ground from the trigger wire. If the reading stays low – the trigger is bad.
Note: If #1 and #2 or #3 and #4 are acting up, check the trigger as described above. The trigger has two coils firing four cylinders. #1 & 2 share a trigger coil and #3 & 4 share a trigger coil. Also, the switch box is divided into two parts. The #1 and #2 cylinders are fired on one side and #3 and #4 are fired from the other side of the switch box. If the trigger tests good by the chart below, but you have two cylinders not firing (either #1 and #2 or #3 and #4), the switch box or stator is bad.
3. If you have two cylinders not firing (either #1 or #2 or #3 and #4), swap the stator leads end to end on the switch box (Red with red/white and blue with blue/white). If the problem moves to the other cylinders, the stator is bad. It the problem stays on the same cylinders, the switch box is likely bad.
4. 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.
Engine will not rev beyond 3000-4000 RPM:
1. Connect an inductive Tachometer to all cylinders and try to isolate the problem. If two cylinders on the same end of the switch box are dropping out, the problem is likely going to be either the switch box or trigger. A single cylinder dropping fire will likely be the switch box or ignition coil. All cylinders acting up usually indicate a bad stator.
2. Connect a DVA meter to the stator’s Blue wire and Blue/White wires and do a running test. The DVA voltage should jump up to well over 200V and stabilize. A drop in voltage right before the problem occurs indicates a bad stator. (Green/White to White/Green if the engine has a Red stator kit
installed).
3. Connect a DVA meter to the Red wire and Red/White wires and do a running test. The DVA voltage should show a smooth climb in voltage and remain high through the RPM range. A reading lower than what is on the Blue wires indicates a bad stator.
High Speed Miss:
1. Connect an inductive Tachometer to all cylinders and try to isolate the problem. A high variance in RPM on one cylinder indicates a problem usually in the switch box or ignition coil. Occasionally a trigger will cause this same problem. Check the trigger as described above under “No fire or Intermittent on One or More Cylinders”.
2. Perform a high-speed shutdown and read the spark plugs. Check for water. A crack in the block can cause a high speed miss when the water pressure gets high, but a normal shutdown will mask the problem.
3. Remove the flywheel and check the triggering and charge coil flywheel magnets for cracks or broken magnets.
Four Cylinder Engines 1996-2000
Four Cylinder Engines Using a Combination Switch Box and Ignition Coil (CDM Modules)
No fire at all:
1. Disconnect the black/yellow kill wires from the harness and retest. If the engine’s ignition fires now, the kill circuit has a fault-possibly the keyswitch, harness or shift switch.
2. Disconnect one CDM module at a time and see if the other modules start firing. If they do, the module you just unplugged is bad.
3. Disconnect the yellow wires from the stator to the rectifier and retest. If the engine fires, replace the rectifier.
4. Check the cranking RPM. A cranking speed less than 250-RPM will not allow the system to fire properly.
5. Check the stator resistance and DVA output as given below:
Wire Read To Resistance DVA
White/Green Green/White 500-700
180V or more
No fire or Intermittent on One or More Cylinders:
1. If the cylinders are only acting up above an idle, connect an inductive RPM meter to all cylinders and try to isolate the problem cylinders.
2. Using a set of piercing probes, check the trigger DVA output as given below:
Wire Read To Resistance DVA
Purple wire(#1)
White wire(#2)
Brown wire(#3)
White/Black wire(#4) Engine GND
Engine GND
Engine GND
Engine GND Open
Open
Open
Open 3V or more
3V or more
3V or more
3V or more
•SERVICE NOTE: These triggers have the bias circuitry built into them, therefore you cannot measure the resistance like you could the older engines. In addition, there are four triggering coils used.
3. Disconnect one of the CDM modules that are firing at a time and see if the dead module start firing. If it does, the module you just unplugged is bad.
High speed miss:
1. Connect an inductive RPM meter to all cylinders and try to isolate the problem. A high variance in RPM on one cylinder indicates a problem usually in the switch box or ignition coil. Occasionally a trigger will cause this same problem. Check the trigger as described above under “No fire or Intermittent on One or More Cylinders”.
2. Perform a high-speed shutdown and read the spark plugs. Check for water. A crack in the block can cause a high speed miss when the water pressure gets high, but a normal shutdown will mask the problem.
3. Remove the flywheel and check the triggering and charge coil flywheel magnets for cracks or broken magnets.
Inline 6 and V6 Engines Using Dual Switch Boxes and Six Ignition Coils No Fire At All:
1. Disconnect the black/yellow kill wires AT THE PACK and retest. If the engine’s ignition fires now, the kill circuit has a fault-possibly the keyswitch, harness or shift switch.
2. Disconnect the yellow wires from the stator to the rectifier and retest. If the engine fires, replace the rectifier.
3. Check the cranking RPM. A cranking speed less than 250-RPM will not allow the system to fire properly.
No fire or Intermittent on One Bank (Odd or Even Cylinders – L-6):
1. Check the stator resistance and DVA output as given below:
9 to 16 Amp Battery Charging Capacity
Wire Read To Resistance DVA
Blue
Blue/White
Red
Red/White Engine GND
Engine GND
Engine GND
Engine GND 5000-7000
5000-7000
90-200
90-200 180V or more
150V or more
25V or more
25V or more 40 Amp Battery Charging Capacity Wire Read To Resistance DVA Blue
Blue/White
Red
Red/White Engine GND
Engine GND
Engine GND
Engine GND 1000-1600
1000-1600
75-90
75-90 150V or more
150V or more
20V or more
20V or more
2. 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 on all cylinders. If the reading is low on one bank and the stator voltage is good, the switch box is likely bad. (Note: A final test to verify which component is bad is to swap the stator leads from one switch box to the other. If the problem moves, the stator is bad. If the same bank stays down, the switch box is bad.)
3. Check the cranking RPM. A cranking speed less than 250-RPM will not allow the system to fire properly.
No fire or Intermittent on One or More Cylinders:
•Note: If two cylinders on separate packs are not firing, check the trigger as described in # 1 below. The trigger has three coils firing six cylinders. #1 and 2 share a trigger coil, 3 and 4 share a trigger coil and 5 and 6 share a trigger coil.
1. Connect a spark gap tester and verify which cylinders are acting up. If the cylinders are only acting up above an idle, connect an inductive RPM meter to all cylinders and try to isolate the problem cylinders.
2. Check the trigger resistance and DVA output as given below:
Wire (yellow sleeve) Read To (black sleeve) Resistance DVA (connected)
Brown wire(#2)
Purple wire(#4)
White wire(#6) Purple wire(#1)
White wire(#3)
Brown wire(#5) 800-1400
800-1400
800-1400 4V or more
4V or more
4V or more
•Note: You should get a high or open resistance reading to engine ground from each wire, but you will get a DVA reading of approximately 1-2 Volts. This reading can be used to determine if a pack has a problem in the triggering circuit. For instance, if you have no fire on one cylinder and the DVA trigger reading for that cylinder is low – disconnect the trigger wire and recheck the DVA out put to ground from the trigger wire. If the reading stays low – the trigger is bad.
3. 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.
Inline 6 and V6 Engines Using Dual Switch Boxes and Six Ignition Coils (continued) Engine will not rev beyond 3000-4000 RPM:
1. Connect an inductive RPM meter to all cylinders and try to isolate the problem. If two or more cylinders on the same bank are dropping out, the problem is likely going to be either the stator or the switch box. A single cylinder dropping fire will likely be the switch box or ignition coil.
2. Check the stator resistance as given below:
9 to 16 Amp Battery Charging Capacity
Wire Read To Resistance
Blue
Blue/White
Red
Red/White Engine GND
Engine GND
Engine GND
Engine GND 5000-7000
5000-7000
90-200
90-200 40 Amp Battery Charging Capacity Wire Read To Resistance Blue
Blue/White
Red
Red/White Engine GND
Engine GND
Engine GND
Engine GND 1000-1600
1000-1600
75-90
75-90
3. Connect a DVA meter to the Blue wire and do a running test. The DVA voltage should jump up to well over 200V and stabilize. A drop in voltage right before the problem occurs indicates a bad stator. Repeat for the blue/white wire and compare the readings.
4. Connect a DVA meter to the Red wire and do a running test. The DVA voltage should show a smooth climb in voltage and remain high through the RPM range. Repeat for the red/white wire and compare the readings.
High Speed Miss:
1. Connect an inductive RPM meter to all cylinders and try to isolate the problem. A high variance in RPM on one cylinder indicates a problem usually in the switch box or ignition coil. Occasionally a trigger will cause this same problem. Check the trigger as described above under ‘No fire or Intermittent on One or More Cylinders’.
2. Perform a high-speed shutdown and read the spark plugs. Check for water. A crack in the block can cause a high speed miss when the water pressure gets high, but a normal shutdown will mask the problem.
3. Remove the flywheel and check the triggering and charge coil flywheel magnets for cracks or broken magnets.
If you have any questions please feel free to contact us or you can purchase a service manual with more help topics and pictures.
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