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ELECTRICAL SYSTEMS
IGN ITION SYSTEM
10-69
Figure
10-83-Result of Under or Over Capacity Condenser
excessive pitting of one contact point and a
cor-
responding build-up of metal on the other
con-
tact point will
result.
A condenser having
insuf-
ficient capacity will cause build-up of metal on
the breaker arm
(positive)
point. See figure
10-83, view A. A condenser having excessive
capacity will cause build-up of metal on the con-
tact support (negative)
point.
See figure 10-83,
view B.
Figure 10-84-Distributor
Parts-1948 Model Shown
10-51 DISTRIBUTOR OVERHAUL
a. Removal of Distributor
1. Disconnect primary wire from distribu-
tor and disconnect pip
e
from vacuum control
unit.
Remove
distributor
cap.
2.
Crank
engine
until dist r ibut or rotor is in
position to fire
No.1
cylinder, and the timing
mark on flywheel aligns with index on flywheel
housing.
3.
Remove the two
distributor
retaining
bolts and lift distributor out of
crankcase.
b. Disassembly of Distributor
1.
Remove rotor
and
br eaker
pla te ground
lead, then r
emove t
he
vacuum cont r ol. See fig-
ure 10-84.
2.
Disconnect
t
erminal
connector
lead
from
terminal
stud,
then remove stud and bushing.
3.
On 1948
Model distributor,
rotate breaker
plate until ball bearings align with vertical
grooves and lift plate and bearings out of
housing.
Condenser testers equipped to check conden-
sers for low insulation
r
esist ance usually give
a reading in
megohms,
a megohm being one
million ohms. The scale is marked to indicate
whether the condenser is
good or bad.
When
testing
a condens er
for
low insulation
resistance
the
lead
should always
be
dis-
connected
from the distributor. S
ee
paragraph
10-46.
Since
the
distributor terminals
and the
connected
circuit
hav
e much lower insulation
resistance
than the
condenser,
fa
ilure
to dis-
connect the
condenser lead
will give a r
eading
much too low.
B. OVER
CAPACITY
A.
UNDER CAPACITY
-
+
c. Low Insulation Resistance
A weak or leaking condenser is usually one
that has absorbed water so that the insulation
resistance of the winding is lowered to the ex-
tent that the condenser will not hold a charge
satisfactorily. A condenser with low insulation
resistance will drain sufficient energy from the
ignition system to lower the secondary voltage
ser ious ly. The condenser specified for use in
t
he Buick ignition system is sealed to prevent
absorption of
water,
and no other type should
be
used.
A leaky condenser usually
does
not affect en-
gine performance
except
when
hot.
It is un
-
likely that a condenser with low insulation re-
sistance would cause missing at low or medium
speeds under conditions where the condenser
does not get hot. A condenser that has low
enough resistance to affect engine performance
when cold would probably be indicated as broken
down on most condenser testers.
In exceptional cases, pitting and metal build-
up on contact points may be experienced even
when condenser capacity is within the specified
limits. In such cases the life of contact points
will be improved by installing a condenser of
high-limit capacity if metal build-up is on
breaker arm
point,
or a condenser of low-limit
capacity if metal build-up is on contact support
point.
There is usually sufficient variation in
the capacities of stock condensers to permit
selection of a high or low limit condenser by
testing the available stock.
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