Mallory Ignition ACCEL CHEVROLET APPLICATIONS (including LT-1) 74022 - Manual (Page 4)

ACCEL/DFI ACCEL/DFI
An overview schematic of the main wiring harness
(MWH) is shown in Figure B (Page 23). The harness can be
routed and connected as follows: Begin by connecting the 32
pin and 24 pin ECM connectors to the ACCEL/DFI ECM,
making sure that the tabs snap into place. Then route the
longer of the two legs through the drivers side firewall hole
that you cut in step two, followed by the shorter of the two
legs though the passenger side firewall hole. Continue
pulling the harness legs through the firewall until the rubber
grommets seat themselves in the firewall. Once the
grommets have been properly seated into the firewall, each
leg of the harness can be routed between the manifold and
the valve covers.
The drivers side leg will contain connectors for the following:
• MAP (3-pin green male connector, refer to
Figure B for mounting location)
• Computer controlled HEI (4-pin male black
connector)
• ESC (1-pin female black connector)
• Air (2-pin Grey connector)
• Coolant (2-pin black connector)
• TPS (3-pin black male connector)
Connect each to the appropriate sensor using Figure B as a
reference. If this is a ACCEL system for an LT-1 engine
(74022-L), there will be an Opti-spark harness that will
connect the Computer controlled HEI connector, a TPS
extension harness, IAC motor adapter as well as adapter
harnesses for the air and coolant sensors. If you are missing
5
III – MOUNTING THE ACCEL ECM
4
The ECM comes with three (3) mounting tabs designed for a
#8 sheet metal screw. It is recommended to mount the ECM
in the passenger side kick panel. If the kick panel has an air
vent incorporated into it, DO NOT mount the ECM here.
This is not waterproof and therefore, needs to be mounted in
a location free of moisture. The alternate location is in the
dash board area behind the glove box. NEVER MOUNT THE
ECM IN THE ENGINE COMPARTMENT!
It is strongly recommended that this harness be installed
prior to mounting the plenum. Refer to Figure A for routing
the injector harness.
This ACCEL/DFI system is simultaneous double fire, therefore,
an injector connector may be connected to any injector, but
for your convenience, the connectors are paired in two’s,
similar to the way the injectors are mounted in the manifold.
Route the injector harness onto the manifold as shown in
Figure A (Page 22). After properly aligning the injector
harness onto the injectors, clip the connectors into place,
making sure that the metal clips snap into place. After the
main wiring harness has been installed, connect the injector
harness round 5-pin female connector to the MWH’s round
5-pin male connector.
IV – INJECTOR HARNESS INSTALLATION
V – MAIN WIRE HARNESS ROUTING
AND CONNECTIONS