Secondary Circuit Tests - Lincoln Continental 1964 Shop Manual

9-6
point assembly consists of the sta-
tionary point bracket assembly,
breaker arm and the primary wire
terminal.
Breaker points should be inspected,
cleaned and adjusted as necessary.
Breaker points can be cleaned with
chloroform and a stiff bristle brush.
Replace the breaker point assembly
. if the contacts are badly burned or
excessive metal transfer between the
points is evident (Fig. 14). Metal
transfer is considered excessive when
it equals or exceeds the gap setting.
Coil. The coil should be tested
following the instructions under
"Ignition System Tests".
Condenser. The condenser should
also be tested following the instruc-
tions under "Ignition System Tests".
TRANSISTOR
IGNITION SYSTEM
When diagnosis procedures isolate
trouble to the primary circuit, make
the following tests to locate the de-
fective items. Do not use any other
procedure, conventional short cut,
or connect test equipment in any
other manner than that described
or extensive damage can be caused
to the transistor ignition system.
Figure 15 shows the transistor igni-
tion system tests in outline form.
Disconnect the cold start relay.
Connect a dwell meter to the tachom-
eter block. Connect the black lead
to the black terminal and the red
lead to the red terminal. Turn the
ignition on and crank the engine.
Observe the dwell meter reading.
oo
Dwell. A dwell reading of
oa
indicates:
1. The distributor points are con-
taminated or are not closing.
oo
to 45° Dwell. A dwell reading
between
oo
and 45° indicates:
1. The transistor and the primary
circuit are functioning properly.
2. The trouble could be in the
secondary circuit.
45° Dwell. A dwell reading of
45° indicates:
1. No power from the ignition
switch.
2. The distributor points are
closed and not opening.
3. Defective amplifier assembly.
To determine which of the three
items listed are causing the trouble
proceed as follows:
~
Disconnect the distributor lead at
the bullet connector, and crank the
engine.
If
the dwell meter indicates
oo
dwell, the distributor points are
GROUP 9-IGNITION SYSTEM
not opening.
If
45 o dwell is indi-
cated, the amplifier is malfunctioning
or there is no power from the ig-
nition switch.
Use a voltmeter or test light to
determine if the transistor (amplifier
assembly) is at fault. Connect the
voltmeter to the red-green lead termi-
nal of the ballast resistor and to
ground. Crank the engine.
If a steady indication of voltage
is obtained, the trouble is in the
amplifier. Absence of any voltage
indication on the voltmeter shows
there is an open circuit, or no power
between the ignition switch and the
amplifier. The ballast resistor could
be defective. Replace it with a known
good ballast resistor, and repeat the
test.
If the test procedure indicates a
defective amplifier, replace it with a
known good amplifier, and proceed
as follows:
Connect the distributor high ten-
sion lead at the bullet connector.
Then, with the cold start relay dis-
connected and the dwell meter con-
nected to the tachometer block,
crank the engine and observe the
indicated dwell. A reading between
oo
and 45° indicates satisfactory
ignition; thus, the amplifier is at
fault.
If the dwell reading is still 45a,
the wiring from the amplifier through
the ballast resistor to the coil is de-
fective. Replace the defective item.
SECONDARY CIRCUIT TESTS
The following procedure is used
on both ignition systems.
PRELIMINARY CHECKS
1. Remove the coil to distributor
high tension lead and the spark plug
wires from the distributor cap and
from the spark plugs. Inspect the
terminals for looseness and corro-
sion. Inspect the wires for breaks
and cracked insulation. Replace all
defective wiring.
2. Clean the inside of the distribu-
tor cap, and inspect it for cracks,
burned contacts, permanent carbon
tracks or a defective center carbon
brush electrode. Remove dirt or cor-
rosion from the sockets. Replace the
cap if it is defective.
3. Inspect the rotor for cracks or
defects. Replace the rotor if it is
defective.
SECONDARY (HIGH TENSION)
WIRES
The secondary wires include the
(182)
wires connecting the distributor cap
to the spark plugs and the wire con-
necting the center terminal of the
distributor cap to the center terminal
of the ignition coil.
These wires are the radio resist-
ance-type which filter out the high
frequency electrical impulses that
are the source of ignition noise inter-
ference. The resistance of each wire
should not exceed 24,500 ohms.
When checking the resistance of
the wires for setting ignition tim-
ing, do not puncture the wires
with a probe. The probe may cause
a separation in the conductor.
At regular intervals, clean and
inspect the wires for cracked insula-
tion and loose terminals .. Repair or
replace the wires as required. A
spark plug wire set is available for
service.
When removing the wires from
the spark plugs, grasp the moulded
cap only. Do not pull on the wire
because the wire connection inside
the cap may become separated or
the weather seal may be damaged.
Spark Intensity
1. Disconnect a spark plug wire.
Check the spark intensity of one
wire at a time.
2. Install a terminal adapter in
the terminal of the wire to be
checked. Hold the adapter approxi-
mately
%ti
inch from the exhaust
manifold and crank the engine, using
a remote starter switch. The spark
should jump the gap regularly.
3. If the spark intensity of all the
wires is satisfactory, the coil, con-
denser, rotor, distributor cap and
the secondary wires are probably
satisfactory.
If
the spark is good at only some
wires, perform a high resistance test
of the faulty leads.
If the spark is equal at all wires,
but weak or intermittent, make a
high resistance check of the coil,
distributor cap and the coil to dis-
tributor high tension wire. Follow
the instructions of the test set manu-
facturer when making the tests.
On the transistor ignition, do
not test the coil on a coil tester,
as inconclusive results will be ob-
tained due to the very low coil
primary inductance. Substitute a
known good coil and perform the
primary circuit tests.
SPARK PLUGS
Clean, inspect and gap the plugs
following the instructions in Sections