MSD 6430 6ALN Ignition Control Installation - Manual (Page 9)

INSTALLATION INSTRUCTIONS 
M S D I G N I T I O N
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MIsses AND INTerMITTeNT PrOBLeMs
Experience at the races has shown that if your engine is experiencing a miss or hesitation at higher rpm,
it is usually not directly ignition. Most probable causes include a coil or plug wire failure, arcing from
the cap or boot plug to ground or spark ionization inside the cap. Several items to inspect are:
• Always inspect the plug wires at the cap and at the plug for a tight connection and visually inspect
for cuts, abrasions or burns.
• Inspect the Primary Coil Wire connections. Because the MSD is a Capacitive Discharge
ignition and it receives a direct 12 volt source from the battery, there will not be any voltage
at the Coil Positive (+) terminal even with the key turned On. During cranking or while the engine
is running, very high voltage will be present and no test equipment should be connected.
WARNING: Do not touch the coil terminals during cranking or while the engine is running.
• Make sure that the battery is fully charged and the connections are clean and tight. If you are not
running an alternator this is an imperative check. If the battery voltage falls below 10 volts during
a race, the MSD output voltage will drop.
• Is the engine running lean? Inspect the spark plugs and complete fuel system.
• Inspect all wiring connections for corrosion or damage. Remember to always use proper connections
followed by soldering and seal the connections completely.
If everything checks positive, use the following procedure to test the ignition for spark. MSD also
offers an Ignition Tester, PN 8998. This tool allows you to check your complete ignition system while
it is in the car as well as the operation of rpm limits, activated switches and shift lights.
CheCkINg FOr sPArk
If triggering the ignition with the White wire:
1. Make sure the ignition switch is in the "Off" position.
2. Remove the coil wire from the distributor cap and set the
terminal approximately 1/2" from ground.
3. Disconnect the MSD White wire from the distributor's
points or ignition amplifier.
4. Turn the ignition to the On position. Do not crank the
engine.
5. Tap the White wire to ground several times. Each time
you pull the wire from ground, a spark should jump from
the coil wire to ground. If spark is present, the ignition is working properly. If there is no spark skip
to step 6 on page 10:
Figure 8 Checking for Spark with the White Wire.
WHITE WIRE TRIGGER
Most other applications: On
other applications where engine
Run-On is experienced, a
Resistor can be put in-line
to the MSD's small Red wire
(Figure 7). This resistor will keep
voltage from leaking through to
the MSD unit.
Figure 7 Wiring the Dual Ballast Resistor for Run-On.