Shibaura ST330, Workshop Manual

Page: 202 / 250

191
7
）
DIODE FOR BRAKE SWITCH
Description
The diode, 1, is in the d ash board of th e
tractor, attached to the tractor wiring
harness.
Diode is electrical devices which current is
allowed to pass in one direction, directing
current within a circuit. Diodes allow the
use of one wire within multiple circuits to
control current flow to electrical
components such as relays.
This diode is p aired to geth er in a singl e
case.
The remaining d iode is housed alon e.
Dio de Testing
1. D isconnect th e negativ e ( － ) battery
cable fro m t he battery.
2. Remov e the dashbo ards from the tracto r.
3.
D isconnect the diode from the wiring
harn ess of the tracto r.
NOTE:
For this test , an electrical multim eter with
diod e test capabilities may be used in place
of an ohmmeter. If a m ultim eter with d iod e
testing capa bilities is unavailable, use an
ohmm eter to test as described below.
4. U sing an oh mmeter, tou ch th e red,
positive (+), test probe to diode
terminal "A". Tou ch the black , neg ative
(
－ ), ohmmeter test probe to d iode
terminal "B". Ob serve th e ohmmeter.
5. Th e oh mmeter s hould show high
resistance, indicating no con tinuity and
that current is not flowing through the
diod e in that direction. If there is
continuity.
C h eck to see that the test
probes are on th e correct terminals, and
if they are, the d iod e is defective and
need s replaced .
6. I f th e prev ious test ind icated the d iod e
was functioning properly, touch the red,
positive (+), oh m meter test prob e to
terminal "B" o f the diode and the black,
negative (
－
), test probe to terminal
"A" of the diode.
7. O bserv e the ohmmeter. The ohmmeter
shou ld show little or no resistance,
indicating continu ity in that direction.
If the oh mmeter does no t show
continuity, the diod e is defective and
need s replaced .
529Y
530Y