MSD 8584 Ford V8 351W Billet Distributor Tech Bulletin - Manual (Page 2)

DISTRIBUTOR MAKE
MSD
CHRYSLER
FORD
GM
MSD 6’ Harness, PN8860
POLARITY +
Black/Orange
White/Orange
Black/Orange
White
Violet
POLARITY -
Black/Violet
Black
Black/Violet
Green
Green
MSD • 1490 Henry Brennan Dr., El Paso, Texas 79936 • (915) 857-5200 • www.msdperformance.com
FRM29562 Revised 01/13 PRINTED IN U.S.A.
Polarity
These pickups can only be connected one way to operate correctly so it is important to know the polarity of the wires.
The magnetic pickup wires of an MSD Ignition Control are twisted together and routed in a separate sleeve with a 2-pin
connector. The Violet wire is positive and the Green wire is negative. This harness connects to the distributor pickup or
a crank trigger pickup. The chart below shows the polarity of MSD Distributors and other models.
If you’re not sure about the polarity of the pickup you are using, there is a simple test you can perform by checking the
engine’s timing. Check the timing with the pickup wires connected one way, then swap the wires and check the timing
again. You will notice that the timing changes significantly and may appear very erratic. The correct connection depends
on the ignition control that is being used.
Analog: If you are using an analog controlled MSD Ignition such as a 6A, 6T or 6AL series, SCI series, 7AL series,
MSD 8 or 10 or Blaster Ignition, the correct connection is when the timing is retarded.
Digital: When using an MSD Digital-6 or Digital-7 Plus, or the Programmable Digital-7 Ignition Controls, the correct
connection is when the timing is more advanced.
Wiring
Routing the magnetic pickup wires can be very important to your engine’s performance. Since the pickups are deliv-
ering a voltage signal to trigger the ignition, it is important that the wires are routed away from other wiring, electrical
components and spark plug wires. This is especially important in today’s performance world with aftermarket EFI sys-
tems, electric water pumps and more.
Notice that the pickup wires are twisted around each other in the PN 8860 harness that MSD supplies with the ignition.
This helps create a field around the wires for protection and should be done with any other wiring of the pickup. Also try
to route the pickup wiring as close to the engine block, frame or chassis of the car. These parts serve as large ground
planes so there is less electrical activity near their surface.
Following these guidelines will help ensure the proper trigger signal from your pickups. MSD also offers a special
Shielded Harness, PN 8862. This harness features a special ground shield that protects the trigger wires from external
interference.
Testing
You can check the resistance of the MSD pickups as shown below. If the value is out of the specifications given, the
pickup is at fault.