2
38
Diode Test
In the DIODE TEST position, the meter will display
the forward voltage drop across the diode(s). If the
voltage drop is less than
0.7 volts
, the meter will
BEEP
once and display the voltage drop. A
CONTINUOUS TONE
indicates
CONTINUITY
(shorted diode) An
INCOMPLETE CIRCUIT
(open
diode) will be displayed as
OL
.
1. Insert RED test lead into
V
receptacle in meter.
2. Insert BLACK test lead into
COM
receptacle in
meter.
3. Rotate selector to
+
)
)
)
))
(DIODE TEST) position.
4. Attach RED test lead clip (1) to point A and
BLACK test lead clip (2) to DC output pin (6),
Fig. 17
. (It may be necessary to pierce wire with
a pin as shown.)
a. If meter
BEEPS
once, diode is OK.
b. If meter makes a
CONTINUOUS TONE
,
diode is shorted. Replace diode.
c. If meter displays
OL
, proceed to step 5.
5. Reverse test leads.
a. If meter
BEEPS
once, diode is installed
backwards. Replace diode.
b. If meter still displays
OL
, diode is open.
Replace diode.
6. If diode tests OK, check stator for bare wires or
other obvious defects. If grounded leads are not
visible, replace the stator.
NOTE:
Service replacement diode harnesses are
available. Use resin core solder when
installing new harness. Use shrink tubing or
tape all connections. DO NOT USE CRIMP
CONNECTORS.
Fig. 17
A
AC Output Test
1. Insert RED test lead into
V
receptacle in meter.
2. Insert BLACK test lead into
COM
receptacle.
3. Rotate selector to
V~
(AC VOLTS) position.
4. Attach RED test lead clip (1) to AC output
terminal (5),
Fig. 18
.
5. Attach BLACK test lead clip (2) to engine
ground.
6. With engine running at 3600 RPM output should
be no less than
14 volts AC
.
7. If
NO
or
LOW
output is found, replace stator.
ÌÌÌ
Ì
Fig. 18
Tri-Circuit Alternator
The tri-circuit alternator provides alternating current
(AC) through a single output lead and connector to
a wiring harness containing two diodes.
One diode rectifies the AC current to 5 amps
NEGATIVE (-) DC for lights. The second diode
rectifies the AC current to 5 amps POSITIVE (+) DC
for battery charging and external loads, such as an
electric clutch.
NOTE:
Some original equipment manufacturers
(OEMs) supply diodes as an integral part of
the equipment wiring harness. Some OEMs
use a 1 Ohm-20 Watt resistor placed in
series with (+) DC charging lead, limiting the
charging current to approximately 3 amps
when the clutch is not engaged. When the
clutch is engaged the resistor is bypassed
allowing full output to the battery and clutch.
