MSD 8870 Coil Interface Block,GM Dual Tower Coils Installation - 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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