Engine Starting Circuit - Doosan DX140R Shop Manual

ENGINE STARTING CIRCUIT

Start Operation
When the starter switch is turned to the "START" position, the
"S" and "E" terminals of the starter controller (7) are connected.
At this time the contacts in the starter relay (8) are closed by the
current flow from the battery (1) → fusible link (3) → fuse box (6)
→ "B" terminal of starter switch (5) → "C" terminal of starter
switch (5) → "30" terminal of starter relay (12) - "87a" terminal →
"C" terminal of starter relay (8) - "D" terminal → "S" terminal of
starter controller (7) - "E" terminal → ground.
When the contact point "B" and "PP" of starter relay (8) are
connected, the pinion gear of the starter (9) is pushed forward
and makes contact with the ring gear of the flywheel and the
internal contacts of the starter are connected. The current flows
from the battery (1) → "A" terminal of the battery relay (2) → "B"
terminal of the battery relay (2, Figure 3) → "B" terminal of the
starter (9). The starter motor is rotated and the engine is started.
If the instrument panel has the password function activated ,
input number should match the set number, otherwise the start
circuit closes and the engine does not start.
If the security system is "LOCKED," a four-digit
NOTE:
password will be required to start the engine. If the
system is "UNLOCKED," no password will be
required and this display screen will not appear.
In the event the security system is locked, current
flows from battery (1)
→
(6) "B" terminal of starter switch (5)
terminal of starter switch (5)
→
relay (12)
"CN1-15" terminal of e-EPOS (13)
current flow causes the coil in starter relay (12) to be
activated, opening contacts at "87a" terminal. This
prevents starter relay (8) from functioning.
Electrical System
Page 10
→
fusible link (3)
→
"86" terminal of starter
"85" terminal of starter relay (12)
→
→
fuse box
→
"ACC"
→
ground. This
Figure 2
ENTER
PASSWORD
FG013717
SP001949