MAINTENANCE MANUAL OF ENGINE
83
4. Dismantling the alternator subassembly
4.1 Inspecting the whole machine prior to dismantling
1. The resistance between terminal “F” and “-” is
4~8Ω. If the resistance is too small, the possible
cause is that the field coil is shorted or the insulat-
ing spacer is damaged; if the resistance is too big,
the possible cause is that the brush contacts with the
slip ring poorly; the resistance is infinite, indicating
that the coil is open.
2. The resistance between terminal “+” and “-” is
30~50Ω, and the reverse resistance is above 10KΩ;
if not, the possible cause is that the rectifier or ar-
mature coil is failed.
3. The resistance between terminal “N” and “-” is
8~10Ω, and the reverse resistance is above 10KΩ; if
not, the possible cause is that the rectifier or arma-
ture coil is failed.
4.2 Dismantling the alternator
1. Dismantle the brush and brush holder.
2. Dismantle the screw caps, pulley, fan, and wood-
ruff key.
3. Dismantle the fastening screw.
4. Use a special tool to dismantle the drive end cov-
er (attention that the stator cannot move together
with it).
5. Remove the rotor assembly.
6. Dismantle the screw caps of the 3 terminals on
the component board, and remove the stator assem-
bly.
7. Dismantle the fastening screws on the component
board, and terminal “+” and “N” on the rear end
cover.
8. Remove the component board (attention that in-
dividual insulating washers cannot be lost).
Attention: For the integral alternator, the built-in
voltage regulator can be removed from the carbon
brush holder.
4.3 Assembling the alternator
1. The alternator is assembled in reverse order.
2. During assembling, the insulating washer be-
tween component board, terminal “+”, “F” and “N”
and the housing cannot be omitted.
3. After being assembled, the alternator should op-
erate flexibly.
Note: For the integral alternator, when the rotor is
installed onto the rear end cover, first install the
carbon brush properly, and fasten the brush onto the
housing with a fine wire, and then install the rotor
in the bearing with a rear end cover to prevent
breakage of the brush.
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