TROUBLESHOOTING
Troubleshooting Fuses, Relays and Harnesses
13-22
6LY3 Service Manual
© 2007 Yanmar Marine International
Troubleshooting Blown Fuses
Blown fuses, their respective circuits and corrective action are shown in the following table. If the fuse blows
again, replace the corresponding wire harness.
No.
Size
Application
Trouble Symptom
Key
Switch
Corrective Action
Engine Stop
Engine Running
1
10A AUX POWER The engine can
start. Error
(P0120 / 0) is
detected. The digital
display will not turn
on.
Error (P0120 / 0) is
detected. The digital
display is not turned
on.
Off
Check the continuity between the negative
(-) side of the fuse and ground (engine
body). In case of continuity, the engine
harness may have a short circuit. Replace
it.
(See Wire Harness Locations on
page 12-18.)
In case of no continuity,
replace the fuse. If the fuse burns out again,
replace the harness.
2
10A IGN PANEL
(Switch panel)
The engine will not
start. ECU will not
turn on.
The engine will shut
down. The engine
cannot start.
Off
Check the continuity between the negative
(-) side of the fuse and ground.
(See Wire
Harness Locations on page 12-18.)
In case
of continuity, replace the fuse. In case of no
continuity, the engine harness may have a
short circuit. Remove the harness 12-pin
connector above the fuel injection pump
and check for continuity again.
(See Wire
Harness Locations on page 12-18.)
In case
of continuity, the engine harness has a
short circuit. Replace it. In case of no
continuity, the TELEFLEX harness may
have a short circuit. Replace it.
3
20A ECU
The engine will not
start. ECU will not
turn on.
The engine shuts
down. The engine
cannot start.
—
Replace the engine harness.
(See Wire
Harness Locations on page 12-18.)
4
10A IGN. SIG
(Switch ON
signal)
The engine starts.
Error (U0146) is
detected.
Error (U0146) is
detected.
On
Check the continuity between the negative
(-) side of the fuse and ground.
(See Wire
Harness Locations on page 12-18.)
In case
of continuity, engine harness may have a
short circuit. Replace it.
(See Wire Harness
Locations on page 12-18.)
In case of no
continuity, replace the fuse. If the fuse
burns out again, main harness may have a
short circuit. Replace it.
5
5A YDT
Engine runs normal
but the YDT is
inoperative.
Engine runs normal.
On
Check the continuity between the negative
(-) side of the fuse and ground.
(See Wire
Harness Locations on page 12-18.)
In case
of continuity, engine harness may have a
short circuit. Replace it.
(See Wire Harness
Locations on page 12-18.)
In case of no
continuity, replace the fuse. If the fuse
burns out again, main harness may have a
short circuit. Replace it.