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INSTALLATION INSTRUCTIONS

LED INDICATOR

A red LED is located on the top of the MSD 6AL. It is used to monitor the current status of the 6AL

ignition.

Key power ON-engine

OFF

Key power ON-engine

OFF

Key power ON-engine

cranking

Key power ON-engine

cranking

One long flash

One long flash + 5

short flashes

Continuous flashing

No flashing

6AL box is

functioning Normal

6AL box is

functioning Normal

6AL box is

functioning Normal

6AL box is

functional

Rev Limiter verification

function active (ON)

Rev limiter verification

function deactivated (OFF)

LED flashes each time the

ignition fires

Check Power, ground and

crank sensor connections

Note: When the engins is running, the LED will appear to be ON. This is normal and is due to the

rapid flashing of the LED on each ignition firing event.

Note: Solid Core spark plug wires cannot be used with an MSD Ignition.

Note: Do not use digital or dial-back timing lights.

REV LIMITER

The Digital 6AL features a built-in Soft Touch Rev Control that provides a smooth and accurate rev

limit by dropping the spark to individual cylinders. The Soft Touch produces a load-free rev limit that

is within 1% of the selected rpm.The rpm limit is adjusted in 100 rpm increments with the sealed

rotary switches under the black cover on top of the 6AL.

CYLINDER SELECT

The MSD is programmed at the factory for use on 8-cylinder engines. If you are installing it to a different

engine you will have to program the Ignition. This is easily achieved through the cylinder select wire

loops on the side of the ignition. Page 5 outlines setting the cylinder select.

GENERAL INFORMATION

BATTERY

The Digital 6A and 6AL will operate on any negative ground, 12 volt electrical system with a distributor.

The MSD can be used with 16 volt batteries and can withstand a momentary 24 volts in case of jump

starts. The Ignition will deliver full voltage with a supply of 9 - 18 volts.

If your application does not use an alternator, allow at least 15 amp/hour for every half hour of

operation. The MSD uses about .9 Amps for every 1,000 rpm. If the engine is cranked with the same

battery or other accessories such as an electric fuel or water pump are used, the amp/hour rating

should be higher.

COILS

The Digital 6A and 6AL Ignition can be used with most stock coils and aftermarket coils designed to

replace the stock coils. The line of MSD Blaster Coils are great for street and mild racing. For extended

high rpm operation the Blaster HVC, PN 8252 or HVC II, PN 8253, are recommended. For more

information on recommended coils, check with our Customer Service Department at (915) 855-7123.

TACHOMETERS

The MSD Ignition features a Gray Tach Output wire that provides a trigger signal for tachometers, a

shift light or other add-on rpm activated devices. The Tach Output wire produces a 12 volt square

wave signal with a 20% duty cycle.

Some vehicles with factory tachometers may require a Tach Adapter to operate with the MSD. For

more information on Tachometers and MSD Tach Adapters, see the Tachometer Section on page 6.

If your GM vehicle has an in-line filter it may cause the tach to drop to zero on acceleration. If this

occurs, bypass the filter.