MSD 7805 8-Plus Ignition Control Installation - Manual (Page 5)

INSTALLATION INSTRUCTIONS 5
M S D
• W W W . M S D P E R F O R M A N C E . C O M • ( 9 1 5 ) 8 5 7 - 5 2 0 0 • F A X ( 9 1 5 ) 8 5 7 - 3 3 4 4
WARNING: Do not touch the coil terminals during cranking or while the engine is running.
• Is the engine running lean or excessively rich? Inspect the spark plugs and fuel system.
• Inspect all wiring connections for corrosion or damage. Remember to always use proper
connections followed by soldering and seal the connections completely.
LED: The LED on the ignition will assist in troubleshooting. If the LED does not flash, there is
no current through the primary coil wires. This could be due to poor connections at the
coil, the coil itself or the ignition. Once you confirm that the trigger signal is working, try a
different coil. See below to test for spark.
If everything checks positive, use the following procedure to test 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. Rapidly tap the White wire to ground several times
(the first 3-4 times will not spark). When the wire is
pulled 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 6:
If triggering with the Magnetic Pickup:
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 magnetic pickup wires from
the distributor.
4. Turn the ignition to the "On" position. Do not crank
the engine.
5. With a small jumper wire, short the MSD’s Green
and Violet magnetic pickup wires together several
times (the first 3-4 times will not spark). Each time you break this ground (rapidly), 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 6.
GREEN
JUMPE R
WIRE
VIOLE T
MAGNETIC PICKUP TRIGGER
WHITE WIRE TRIGGER
Figure 6 Checking for Spark with Magnetic Pickup.
Figure 5 Checking for Spark with a White Wire.