Mallory Ignition ACCEL 275_300 digital ignition 49275_49300 - Manual (Page 3)

WARNING: The 275+ and 300+ Ignition Controls are
capacitive discharge ignitions. High voltage is present at
the coil primary terminals. Do not touch these terminals
or connect test equipment to them.
COMMON COLORS FOR MAG PICKUP WIRES
Distributor Mag + Mag –
Mallory Crank Trigger Purple Green
Mallory Billet Competition Distributor,
Series Nos. 81 and 84
Orange Purple
Mallory COMP® 9000 Series Nos. 96-99 Orange Purple
Mallory Harness P/N 29040 Red Black
MSD Orange/Black Violet/Black
MSD Crank Trigger Orange/Black Violet/Black
Ford Orange Purple
Accel 46/48000 Series Orange/Black Violet/Black
Accel 51/61/71000 Series Red Green
Chrysler Orange/White Black
PRE-START CHECKLIST
• The only wires connected to the coil terminals should be
the yellow connected to coil positive (+) and brown
connected to coil negative (–).
• The red wire is connected to a switched 12 volts source,
such as the ignition key.
• If you’re not using an alternator, the battery should be
connected and fully charged.
• The engine is equipped with at least one ground strap to
the chassis.
TROUBLESHOOTING
This section offers several tests and checks you can perform
to ensure proper installation and operation of the 275+ or
300+ Ignition Controls. If you experience a problem with
your 275+ or 300+, first check for proper installation and poor
connections. You can eliminate many problems by checking
these items. If you have any questions concerning your 275+
or 300+ Ignition Controls, contact the ACCEL Technical
Service Department at 216.688.8300 ext. 5, Monday through
Friday, 8:30 am to 5:00 pm Eastern Standard time.
Tach/Fuel Adapters
If your tachometer does not operate correctly, you probably
need an ACCEL or Mallory tach adapter. Consult the
Tachometer Compatibility List at right for common
tachometers and compatible tach adapters.
No-Run on Foreign Vehicles
Some foreign vehicles with fuel injection systems may
require a tachometer/fuel injection adapter to run with the
275+ or 300+ Ignition Controls. Often, the same trigger
source is used to operate an ignition, tachometer, and fuel
injection. This results in a voltage signal that is too low to
trigger the fuel injection. A tach/fuel injection adapter will
usually solve this problem.
Inoperative Tachometers
If your tachometer fails to operate with the 275+ or 300+
installed, you may need an ACCEL or Mallory tach adapter.
Before purchasing a tach adapter, try connecting your
tachometer trigger wire to the green wire of the 275+ or 300+
Ignition Controls. This output produces a 12 volt, square
wave. If the tach still does not operate, you will need a tach
adapter.
Two different tach adapters are available:
Mallory If you are using the magnetic pickup
P/N 29078 connector (green and violet wires) to trigger
the 275+ or 300+, you will need this adapter.
ACCEL If your tach was triggered from the coil
P/N 49365 negative terminal (voltage trigger) and you
are using the white wire to trigger the 275+
or 300+, you will need this adapter.
TACHOMETER COMPATIBILITY LIST
Aftermarket White Wire Magnetic Trigger
Tachometer Trigger Connector
Autogage 49365 29078
Autometer — —
Ford Motorsport — —
Moroso — —
Stewart 49365 29078
S.W. & Bi Torx — —
Sun 49365 29078
VDO N/A 29078
AMC (Jeep) 49365 29078
Chrysler 49365 29078
Ford (Before 1976) 49365 29078
Ford (After 1976) 49365 29078
GM Bypass in-line Bypass in-line
filter filter
Imports 49365 29078
Misses and Intermittent Problems
Experience has shown that if your engine is misfiring or
hesitating at higher RPM, it is usually not an ignition controller
problem. Most common causes include a coil or plug wire
failure, arcing from the cap or boot plug to ground or spark
ionization inside the cap. Perform the following checks:
• Inspect the plug wires at the cap and at the spark plug for a
tight connection. Visually inspect for cuts, abrasions, or burns.
• Inspect the primary coil wire connections. Because the 275+
and 300+ Ignition Controls receive a direct 12 volt source
from the battery, there will not be any voltage at the coil
positive (+) terminal, even with the key turned on. During
cranking, or while the engine is running, very high voltage
will be present and no test equipment should be connected.
WARNING: Do not touch the coil terminals during cranking
or while the engine is running.
• Make sure that the battery is fully charged and the
connections are clean and tight. If you are not running an
alternator, this is an imperative check. If the battery voltage
drops below 10 volts during a race, the 275+ or 300+
Ignition Controls output voltage will drop.
• Is the engine running lean? Inspect the spark plugs and the
entire fuel system.
• Check all wiring connections for corrosion or damage.
Remember to use proper connections followed by
soldering, then seal the connections completely.
If everything checks positive, use the procedure below to test
the ignition for spark. Mallory offers an Ignition Tester (P/N
28357) that allows you to check the entire ignition
system while it is installed in the vehicle. This tool also
checks operation of RPM limits, activated switches, and
shift lights.
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