INSTALLATION INSTRUCTIONS

7

Tachometer Compatibility List

AFTERMARKET TACHOMETER

WHITE WIRE TRIGGER

MAGNETIC TRIGGER CONNECTOR

AUTOGAGE

8910

8920

AUTOMETER

NONE

NONE

FORD MOTORSPORTS

NONE

NONE

MALLORY

NONE

NONE

MOROSO

NONE

NONE

STEWART (voltage triggered)

8910

8920

S.W. & BI TORX

NONE

NONE

SUN

8910

8920

VDO

NONE

NONE

AMC (JEEP)

8910

8920

CHRYSLER

8910

8920

FORD (voltage triggered)

8910

8920

GENERAL MOTORS

Bypass In-Line Filter

Bypass In-line filter

IMPORTS

8910

8920

Note: On the list above, the trigger wire on tachometers that are marked NONE may be connected to the Gray

Tach Output Wire on the MSD 6AL-2 Ignition.

Figure 4 Common Tachometers and Adapters.

NO-RUN ON FOREIGN VEHICLES

Some foreign vehicles with fuel injection systems may require an MSD Tach/Fuel Injection Adapter

to run with an MSD 6 Series Ignition. This is because many of these systems use the same trigger

source to operate the MSD, the tachometer and the fuel injection. This results in a voltage signal

that is too low to accurately trigger the fuel injection. To fix this, an MSD Tach Adapter, PN 8910, will

remedy the problem on the majority of vehicles. If the PN 8910 does not fix the problem, the PN

8910-EIS will be required.

Note: Toyotas and Ford Probes will require the PN 8910-EIS Adapter.

INOPERATIVE TACHOMETERS

If your tachometer fails to operate with the MSD installed you may need an MSD Tach Adapter. Before

getting an Adapter, try connecting your tachometer trigger wire to the Gray tach wire of the MSD. This

output produces a 12 volt, square wave (see page 2). If the tach still does not operate, you will need

a Tach Adapter. There are two Tach Adapters:

PN 8920: If you are using the Magnetic Pickup connector

(Green and Violet wires) to trigger the MSD, you will need

the PN 8920.

PN 8910: If your tachometer was triggered from the coil

negative terminal (voltage trigger) and you are using the

White wire to trigger the MSD you will need the PN 8910.

BALLAST RESISTOR

If you have a current trigger tach (originally coil positive)

and use the White wire of the MSD, you can purchase a

Chrysler Dual Ballast Resistor (used from 1973 - 1976)

and wire it as shown in Figure 5.

ENGINE RUN-ON

If your engine continues to run even when the ignition

is turned Off you are experiencing engine Run-On. This

usually only occurs on older vehicles with an external

voltage regulator. Because the MSD receives power directly

1A-100V DIODE

FORD VEHICLES

ATTACH DIODE TO TERMINAL "1"

EARLY GM VEHICLES

ATTACH DIODE TO TERMINAL "4"

TO

CHARGING

LIGHT

SPLICE HERE

1

2

3

4

Figure 5 Wiring the Dual Ballast Resistor.

Figure 6 Installing the diode to a GM or Ford Vehicle.