ENGINE MAINTENANCE INSTRUCTIONS
Section I. ENGINE ACCESSORIES
111. Engine Generator Regulator
a. On-engine Testing. Defects in the gener-
The engine accessories consist of the ignition
ator or regulator are indicated on the ammeter
magneto, electrical engine starter, generator,
by a continuous high-charging rate when the
and generator regulator. The magneto is a
battery is fully charged, or by a low-or no-
flange-mounted type. A permanent magnet,
charging rate when the battery is low.
mounted on the rotor shaft, produces a high
(1) When a high-charging rate is indi-
voltage current as its field passes through a
cated, run the engine at operating
fixed coil. The current produced is fed to the
speed and disconnect the lead. from
spark plugs at the proper instant by a distrib-
the field terminal. If the output re-
utor, The electrical engine starter is a 6-volt,
mains high, the trouble is in the gen-
4-brush, bendix-drive type, The starter con-
erator. Replace or repair a defective
verts electrical energy from the battery into
generator (par. 112). If the output
mechanical power and transmits this power to
drops off, the trouble is in the regu-
the engine flywheel for electrical starting. The
lator. Replace a defective regulator.
engine accessory generator is a 6-volt, shunt
(2) When a low or no charging rate is
wound, 2-bush, belt-driven, direct-current gen-
indicated, inspect for loose connec-
erator used to supply current for charging the
tions, frayed or damaged wires, or a
6-volt battery of the test stand. The generator
defective battery. If none of these
regulator is a 6-volt unit provided to control the
conditions exist, operate the engine at
charging current from the generator to the
medium speed and momentarily
ground the field terminal of the regu-
lator. No increase indicates a defect
110. Armature Relay Replacement
in the generator. Repair or replace a
defective generator (par. 112). An
(1) Tag and disconnect the electrical wires
increase indicates the regulator is
and cables from the terminals of the
faulty. Replace a defective regulator.
armature relay (18, fig. 17).
(1) Disconnect the battery terminal adap-
(2) Remove the two hex nuts (19), lock-
ters (7, and 8, fig. 17).
washers (20), flat washers (21), and
(2) Remove the four screws (24) that se-
bolts (22) that secure the relay to the
frame and remove the relay.
cure the cover (23) to the box as-
sembly (28) and remove the cover.
(3) Tag and disconnect all electrical wires
(1) Position the armature relay (18) on
from the engine generator regulator
the frame and secure with the two
bolts (22), flat washers (21), lock-
(4) Remove the three screws (26) and
washers (20), and hex nuts (19).
lockwashers (27) that secure the reg-
(2) Connect the electrical wires and-cables
ulator in the box assembly and remove
to the armature relay.