Msd 8870 Coil Interface Block,GM Dual Tower Coils Inst- User Manual

PARTS INCLUDED:

SPECIAL TOOLS REQUIRED:

1 - DIS Coil Interface Module

Volt Meter

4 - Retaining Screws

1 - Gasket

The MSD DIS Coil Interface Modules are designed to

ease installation of an MSD DIS Ignition Control to GM

vehicles with coil packs. The Interface Module separates

the coil terminals and the ignition module terminals.

The Interface Module has four wires; two White and

two Black wires, that connect to the MSD DIS Ignition.

The White wires carry the MSD high voltage to the coil

terminals.

The Black Wires are responsible for triggering the MSD

and supplying a 12 volt ignition source (Figure 1).

MSD DIS Coil Interface Module

PN 8870

Factory ignition modules are not consistent in which terminal of the ignition module supplies 12 volts.

In order to properly install the DIS Ignition, you will need to confirm which terminal of the ignition

module supplies 12 volts. To do this, a volt meter is required. Before beginning the installation, review

the MSD DIS Ignition Control instructions.

Figure 1 Interface Module Wiring.

1. Mark the location of each spark plug wire and its

corresponding coil pack. Remove the spark plug

wires from the coils.

2. Remove the two bolts that retain the coil packs and

remove the coil from the factory ignition module.

3. There will be two male terminals beneath each

coil pack. To ensure which terminal is the 12 volt

source, use a volt meter and probe (test) each

terminal, with the ignition turned On (Figure 2). A

blank diagram is supplied in Figure 4 that allows

you to note your vehicle's wiring.

Figure 2 Identifying 12 Volts.

Note:

Some applications require that the engine

be cranked momentarily before 12 volts are

present on the terminal. Check all of the

terminals with the key On. If 12 volts is not

present, check the terminals while cranking

the engine. Note the 12 volt terminals.

With the key on, locate the

terminal with 12 volts.

It may be nessary to crank

the engine.

M S D  

•   W W W . M S D P E R F O R M A N C E . C O M   •   ( 9 1 5 )   8 5 7 - 5 2 0 0   •   F A X   ( 9 1 5 )   8 5 7 - 3 3 4 4

WARNING:

During installation disconnect the battery cables. When disconnecting the

battery, always remove negative cable first and install it last.

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