ALTERNATOR
Dual Circuit- Fuse Type
Fig. 182 - Checking for Grounded Charging Coils
Testing Rectifier
Attached to the blower housing baffle is a small black
rectifier assembly.
The rectifier is tested with a multimeter as follows: Three
leads from the rectifier connect to pins in the detachable
plug. See Figure 183. Leave rectifier installed on blower
housing. Test rectifier with multimeter (using resistance
scale) to check resistance from the red lead pin to
blower housing (in an unpainted clean area). See Figure
183.
After checking pin, reverse meter leads and recheck.
The meter should show a reading in one direction only.
If the rectifier pin shows a meter reading both ways, the
rectifier is defective. If the pin shows no reading either
way, the rectifier is again defective.
Leaving one probe on blower housing, repeat with each
black lead pin. Again meter should show continuity in
one direction only, otherwise rectifier is defective. Now
try between red lead pin and each black lead pin. Again,
when probes are interchanged, meter should show
continuity in one direction only.
Fig. 183 - Testing Rectifier
Testing Alternator AC Circuit (Lighting)
Connect load lamp to AC output plug and ground as
shown in Figure 184. Load lamp should light to full
brilliance at medium engine speed. If lamp does not
light, or is very dim at medium speeds, remove blower
housing and flywheel. Disconnect ground end of AC coil,
which is attached to the retaining clamp screw as shown
in Figure 185.
Fig. 184 - Testing AC Light Circuit Output
With multimeter, check continuity between ground lead
of AC coil and AC output terminal as shown in Figure
185. Meter should show continuity.
Fig. 185 - Testing AC Circuit for Continuity
Next, be sure ground lead terminal is not touching a
grounded surface, and check continuity from terminal to
ground.
Meter should not show continuity. If meter indicates
continuity, coils are grounded and defective. Examine
both (white) leads to be sure the insulation is not worn or
cut. Repair with tape and shellac if a bad spot is found.
If ground still exists, or if AC coils do not show continuity,
stator must be replaced.
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