4

INSTALLATION INSTRUCTIONS

WIRING

GENERAL WIRING INFORMATION

Wire Length: All of the wires of the MSD Ignition may be shortened as long as quality connectors

are used or soldered in place. To lengthen the wires, use one size bigger gauge wire (12 gauge for

the power leads and 16 gauge for the other wires) with the proper connections. All connections must

be soldered and sealed.

Grounds: A poor ground connection can cause many frustrating problems. When a wire is specified

to go to ground, it should be connected to the battery negative terminal, engine block or chassis.

There should always be a ground strap between the engine and the chassis. Always securely connect

the ground wire to a clean, paint free metal surface.

Ballast Resistor: If your vehicle has a ballast resistor in-line with the coil wiring, it is recommended

to bypass it.

This wire is responsible for turning the MSD On and Off. Connects

to a switched 12 volt source such as the ignition key or switch. (Max

current draw of .250 mA.)

This wire connects to the coil positive (+) terminal. This is the

ONLY

wire that makes electrical contact with the positive coil terminal.

This wire connects to the coil negative (-) terminal. This is the

ONLY

wire that makes electrical contact with the negative coil terminal.

There are two circuits that can be used to trigger the MSD Ignition; a

Points circuit (the White wire) and a Magnetic Pickup circuit (the Green

and Violet wires). Only one circuit will be used at a time.

This wire is used to connect to breaker points, electronic ignition amplifier

output or to the Yellow wire of an MSD Timing Accessory.

When this

wire is used, the Magnetic Pickup connector is not used.

These wires are routed together in one harness as the magnetic pickup

connector. The connector plugs directly into an MSD distributor or

crank trigger. It will also connect to aftermarket pickups. The Violet

wire is positive (+) and the Green wire is negative (-).

When these

wires are used, the White wire is not.

Tach output wire. Connects to the tachometer trigger wire or other

rpm activated device.

These are the cylinder-select wire loops. Cut one loop for even-fire

6-cylinders, two loops for 4-cylinders.

The Digital 6A and 6AL use a main wiring harness that connects to the ignition through a sealed

and locked connection.

Red

Orange

Black

Trigger

Wires

White

Violet

and Green

(Magnetic

Pickup

Connector)

Accessories

Gray

Red Loop

Blue Loop

These are the two heavy 12 gauge wires and are responsible for getting

direct battery voltage to the ignition. The Ignition is load protected

from reverse battery connections.

This wire connects directly to the battery positive (+) terminal or a

positive battery junction such as the starter solenoid.

Note: Do not

connect to the alternator.

This wire connects to a good ground, either at the battery negative

(-) terminal or to the engine.

Power Leads

Heavy Red

Heavy Black