MSD 6421 User Manual

14 INSTALLATION INSTRUCTIONS
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GM IGNITIONS Wiring with an MSD Wiring Harness.
HARNESS PN 8877
FACTORY HARNESS
(UNPLUGGED FROM COIL)
COIL
MAGNETIC PICKUP
(NOT USED)
HEAVY RED
HEAVY BLACK
TO BATTERY
TO BATTERY
+
RED
GREEN (-)
VIOLET (+)
WHITE
BLACK ORANGE
BLUE
WHITE/BLUE
HALL-EFFECT
(NOT USED)
2-STEP/LAUNCH
(12V TO ACTIVATE)
GRAY
TACH OUTPUT
Harness PN 8876 - Dual Connector Coil.
Harness PN 8877 - 1996-on GM Vehicles.
MSD SYSTEMS Wiring with an MSD Power Grid
MSD
CAN
GREEN - STEP 5
LT. GREEN - STEP 4
TAN - STEP 3
VIOLET - STEP 2
PINK - STEP 1
BLUE - LAUNCH
LT. BLUE - BURN OUT
BRN/WHITE - RPM/TIME SWITCH
WHITE - POINTS IN (NOT USED)
GRAY - TACH
YELLOW - SHIFT LIGHT
GREEN
GREEN
VIOLET
VIOLET
INDICATES CONNECTION
HEAVY RED
HEAVY BLACK
ORANGE
BLACK
V-NET
CABLE
LEGACY IGNITION
(NOT USED)
ORANGE
BLACK
+
+
-
-
BATTERY
POSITIVE
BATTERY
NEGATIVE
PN 8253
MAGNETIC PICKUP
(NOT USED)
FROM IGNITION KEY
(ORIGINAL COIL + WIRE)
IGNITION KEY
TO 12V
ORANGE (TO COIL +)
BLACK (TO COIL -)
RED
GREEN (-)
VIOLET (+)
WHITE
BLUE
GRAY
TACH OUTPUT
WHITE/BLUE
HALL-EFFECT
(NOT USED)
2-STEP/LAUNCH
(12V TO ACTIVATE)
RED

MSD 6421 Specifications

General

Brand	MSD
Model	6421
Category	Control Unit
Language	English