Merc-O-Tronics 98 - INTERNAL REGULATOR CHECKS; Transistor Checks

TRANSISTOR
':ii,
RTGUIATOR
tu:e
1.
2.
3.
4.
5.
Figure
37
INTERNAI REGUTATOR CHECKS
The components
inside
the regulator may
be
checked with
the regulator
connected
in the
circuit
as shown
in Figure 30.
IRANSISIOR
To
check
the transistor,
connect
a voltmeter from
the regulator
"F"
terminal to
ground (Fig.
37).
Close
the switch without
starting
the
engine, and
note
the
voltmeter
reading.
A
reading of approximately
1
to
2 volts is
normal.
If
the reading
is zero volts,
the transistor is shorted.
An
intermittent
short
between
the leads from the field
winding to the
regulator
(marked
"A"
and
"B"
on
the wiring
diagram,
Fig.
30),
an
open
reguiator
field
discharge
diode, an open
suppression
diode,
or
excessive heat can
cause
the transistor to become shorted.
If
the
reading
is
approximately 8
to
9
volts
the transistor
is
burned
open.
7.
An open
transistor
can
result from
a
direct
short between
the
field
winding ieads
(t(A't
and
'(8"
in
the
wiring
diagram, Fig.30), or
from interchanging the leads
at
the regulator
((F"
and
"BAT"
terminals.
6.
JI