2

INSTALLATION INSTRUCTIONS

WIRING

Wiring the 7AL-3 will be simple by following the instructions. There are several color coded wires

supplied with the 7AL-3 and should be used as noted to avoid confusion or wrong connections. This

section is also broken down into two sections; Primary Wiring and Optional Wiring.

• ThePrimarysectiondesignatesthewiresthatmustbeconnectedtoruntheengine.

• TheOptionalWiringsectionexplainsthewiringofoptionalbuilt-infeaturessuchastheRevControls,

RPM Activated Switch and Retard Controls. This information starts on page 6.

WARNING: The 7AL-3 produces very high voltages. Never short the battery or coil terminals. Use

caution during installation and while working near the ignition.

PRIMARY WIRING

1. Begin wiring the MSD by connecting the wires responsible to run the engine. The terminal strip on

the left side of the box is responsible for the Power Leads and the Coil Wires. Connect the supplied

wires as follows:

Heavy Red: Connect from the “Batt +” terminal directly to the battery positive (+) terminal.

Heavy Black: Connect from the “Batt -” terminal directly to the battery negative (-) terminal.

Orange: Connect from the “Coil +” terminal to the positive terminal (+) of the coil (570V).

Black: Connect from the “Coil -” terminal to the negative terminal (-) of the coil (Ground).

2. Move to the middle terminal strip and locate the terminal marked “Ignition”. Use the supplied RED

wire and connect it to a switched 12 volt source (ignition switch).

3. If a retard function is not going to be used the supplied "zero" degree module must be installed.

See the Multi-Step Retard Section.

4. The three terminals on the bottom of the middle terminal strip receive the trigger signal from the

distributor. One terminal is for points style applications and the other two are for use with a magnetic

pickup trigger, such as an MSD Billet Distributor or Crank Trigger.

Note: The Points and Mag Pickup terminals will never be connected at the same time.

Points: If you are using a Points style distributor or electronic amplifier, only the “Points” terminal

will be used. Connect the supplied WHITE wire from the points output in the distributor to the “Pnts”

terminal (Figure 1).

Magnetic Pickup: If you are using an MSD Distributor or Crank Trigger, only the Magnetic Pickup

terminals will be used. Locate the supplied harness with a VIOLET and GREEN wire with a 2-pin

connector on one end. Connect the VIOLET wire to the

“Mag +” terminal and the GREEN wire to the “Mag -”

terminal then connect the 2-pin connector to the Distributor

(Figure 1).

Magnetic Pickup Polarity

The MSD 7AL-3 can be used with other magnetic pick-up

distributors as long as the wires are connected correctly.

The chart on the right shows the polarity of some common

magnetic pickups.

Common Mag Pickup Wires

Distributor

Colors

Mag+

Mag-

MSD

Org/Blk

Vio/Blk

MSD Crank Trigger

Violet

Green

Ford

Orange

Purple

Org/Blk

Vio/Blk

Red

Black

Chrysler

Org/Wht

Black

Mallory

Org/Blk

Vio/Blk

Figure 1