Electronic Governor Troubleshooting - Westerbeke 5.0KW BCG-60Hz Service Manual

Problem
System appears dead.
(No actuator movement)
Engine runs, but at idle speed
Actuator lever goes to full
extension when the preheat
switch is depressed and stays
extended.
ELECTRONIC GOVERNOR TROUBLESHOOTING
Test/Check
1. Check the battery voltage at the controller terminal block
with the Preheat/On switch depressed.
2. Inspect the linkage for binding or sticking.
3. If there is no signal or a weak signal from the
MPU, measure the AC voltage between the white
and black/white wire leads from the MPU on the controller
terminal block. While cranking the engine or with the engine
running at idle, voltage should be 1.5-2.5 VAC.
NOTE: The AC input impedance of meter must be
5000 ohms/volts or greater.
NOTE: When making this test on diesel units, disable
the preheat solenoid by disconnecting the
"s"
terminal
connection so as not to damage the glow plugs.
4. Check the actuator with the preheat/on switch depressed.
This provides DC voltage to the controller. Measure the
DC voltage between the actuator connections on the
controller block and the black DC (-) power connection
on the controller terminal block. Both connections should
have battery voltage +0.00 or -0.75 VDC.
a.
Purple lead to Black DC (-).
b. Purple lead/purple/white lead to Black DC (0).
NOTE: Continue this test (ONLY) if the battery
voltage is not present.
c. The following checks are performed between the
connections at the actuator and the Black DC (-) connection
on the controller terminal block. This is to determine if there
is a break in the line between the controllers terminal block
connection and the actuator connections or the actuator
leads themselves.
1) Low voltage (1.0-2.0 VDC) at either actuator connections.
2) Battery voltage at both actuator connections.
3) Battery voltage at one actuator connection but
not at the second.
1. Check the controlier by removing the two. purple leads
one at a time that come from the actuator off the controlier
terminal block. Lift one actuator lead and depress the
preheat/on switch. Reconnect and do the same with the second.
NOTE: Ear/y controllers had two solid purple leads for the
actuator connections. Later model controllers have one solid
purple and a purple/white stripe for the actuator connection.
The purple/white lead is designated (+) and is specific only in
gasoline DC circuits.
a. Actuator goes to full extension (Diesel),.
Does not retract (Gasoline).
b. Actuator does not extend (Diesel).
Correct
1. Inspect the DC circuit back to the starting battery.
2. Free up the linkage and clean and lubricate the linkage.
3. Check for damage to or improper adjustment of
magnetic pick-up. Replace or re-adjust.
4. Low voltage (1.0-2.0 VDC) at either actuator connections.
b. Replace the controller if battery voltage is not present at
both the Purple leads.
1) Broken actuator lead, repair.
2) Broken actuator lead, repair or replace actuator.
3) Check actuator winding for open. Replace actuator.
1. Check for a shorted actuator lead. Replace the
controller because it should not cause the actuator
lever to go to full fuel when the engine is not running.
a. Check for shorted actuator load.
b. Replace controller.
Actuator hunts during operation. 1. Linkage or rod end bearings are sticking or binding.
1. Lubricate or replace.
2. Improper governor adjustment.
3. Inadequate power supply voltage.
a. Connect a DC voltmeter to Red (+) and Black (-) leads
at the controller terminal block.
b. Disconnect both leads coming from actuator from
controller terminal block.
c. Connect one lead from the actuator to the Red (+)
on the terminal block and the other actuator lead to
the Black (-)on the terminal block.
d. Momentarily depress the preheat/on switch. The actuator
should extend fully and stay extended (diesel) and
retract (gasoline) as long as the switch is depressed.
2. Re-adjust the calibration.
3. If actuator doesn't fully extend (diesels) or retract
(gasoline)then check the actuator leads.
If the voltage is less than specified, check for
loose or poor connections in the DC circuit back to
the battery, check the K2 relay and its connections.
Measure the DC voltage across the Red (+) and Black (-)
leads while perfOrming this test. DC voltage must be greater
than 80%
0
the DC voltage measured across the battery supply.
24 VDC
@
80%
=
19.2 VDC
12 VDC
@
80% = 9.6 VDC
NOTE: Reconnect the actuator leads properly after completing this test.
e. MPU pOSitioned marginally too far away from flywheel e. Check the position of the MPU.
teeth giving erratic AC input to controller.
If
problems continue to perSist, contact your WESTERBEKE dealer for additional assistance.
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&
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