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8-32
ALTERNATOR AND REGULATOR
4.-
0
e3
NK111
Fig. I L T e s t i n g the Air Cap
(d)
Insert an .052 inch wire gauge between the
armature and the voltage coil core, next to the stop
pin on the armature.
(e) Press down on the armature until it contacts
the wire gauge. The upper contacts should remain
closed
and test lamp should remain
bright.
If an adjustment
is required to obtain the
differ-
ence between the upper contact voltage and the lower
contact voltage of .2 volt to
.7
volt; adjust the air gap
by loosening the stationary contact bracket screw
and moving the bracket up
or
down as necessary to
obtain the proper air gap setting as follows:
If the difference
is
above
.7
volt, reduce the air gap
to a minimum of
.045
inch with the contacts open and
the test lamp dim. At
.048
inch the contacts should
close and the test lamp should be bright.
If the difference is below .2 volt, increase the air
gap to a maximum of
.055
inch with the contacts
closed and the test lamp bright. At
.052
inch contacts
should
be
open and test lamp should be dim.
NOTE: Make sure the air gap is checked with the
stationary contact bracket attaching screw fully
tightened.
Voltage Regulator Fusible Wire
Replacement
(1)
Cut the fuse wire above the solder connection
at the base and unwind the wire at the top bracket.
CAUTION: If an attempt is made to unsolder the
old fuse, the very small wire from the voltage coil
may
be
damaged.
(2) Tin the end of the fuse wire.
Use resin core
solder only.
-.
(3)
Holding the tinned end of the new fuse wire
into the recessed rivet at the base of the regulator
and against the old piece of fuse wire that remains,
cause a drop of solder from a soldering iron to fall
on these parts. Allow solder to cool sufficiently for
fuse wires to make a good solder joint.
(4)
Pull the new fuse wire up enough to remove
the slack and wrap it around the bracket. Solder the
coiled wire to the bracket and cut off surplus fuse
wire.
NOTE: The original fuse wire is machine wound on
the upper bracket. The replacement fuse should
be
soldered to the bracket to ensure a good electrical
contact.
ALTERNATOR SERVICING
If the alternator performance does not meet cur-
rent output specifications limits,
it
will have to be re-
moved and disassembled for further test and servic-
ing.
(1)
Disconnect the battery ground cable at the bat-
(2) Disconnect the alternator output "BAT" and
(3)
Remove the alternator mounting bolts and re-
tery negative terminal.
field
"FLD" leads and disconnect the ground wire.
move the alternator.
BENCH TESTS
Field Coil Draw Test
If the alternator field coil draw has not been tested
on the vehicle it may be tested on the test bench as
follows:
(1) Connect the test ammeter positive lead to the
battery positive terminal of a fully charged battery.
Connect the test ammeter negative lead to the field
terminal of the alternator. Connect a jumper wire to
the negative terminal of the battery, and ground it
to the alternator end shield.
(2)
Slowly rotate the alternator rotor by hand.
Ob-
serve the ammeter reading. The field coil draw should
be 2.3 amperes to 2.7 amperes at 12 volts.
NOTE: A low rotor coil draw is an indication of
high resistance in the field coil circuit, (brusher,
slip rings, or rotor coil). A higher rotor coil draw
indicates a possible shorted rotor coil or a grounded
rotor.
Testing Alternator lnternal Field Circuit
for
Ground
(1)
To test the internal field circuit for a ground,
remove the ground brush. Touch one test prod from
a
110
volt test lamp to the alternator insulated brush
terminal and the remaining test prod to the end
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