Ford VSG-411 Service Manual page 110

0698
Governor
06-8
ELECTRONIC DIAGNOSIS AND TESTING
This governor system is comprised of three major
components: the carburetor, actuator and controller. The
objective of this document is to help a technician identify
which component is creating a problem so it can be fixed or
replaced.
CONDITION
I. Governor
appears
dead.
POSSIBLE SOURCE
1 g Battery power is not
supplied to controller.
ACTION
Remove the connector from the controller and with a voltmeter check for
battery power across pins A & B of the wiring harness connector.
If battery power is not present, check wiring to the controller.
2. Controller is not
receiving the speed
signal
NOTE: This controller
receives its speed signal
from the ignition.
If the controller is connected to an engine with a distributor, pins C & D
should both be connected to the negative side of the coil, or the
tachometer output.
If the controller is connected to an engine with a DIS ignition, pin C should
be connected to one of the two tachometer outputs, and pin D should be
connected to the other tachometer output. The DIS ignition utilizes two
coils.
NOTE: Do not short the tach leads; doing so could damage the spark
controller.
Using an ohmmeter, check continuity from pins C & D to the termination
points. If continuity is not present, repair the wiring.
3. Actuator fails to
operate.
Remove the 2-pin connector at the actuator. With a DC voltmeter, check
between the purple wire and chassis (battery) ground. The voltmeter
should read 12 volts, & 2 volts.
If the voltage is low, disconnect the 8-pin connector from the controller, and
check continuity between the wiring harness pins E & F, to their respective
actuator terminals. If there is no continuity, check for openings in the wires.
Using a voltmeter, check for battery voltage from controller terminal E to
chassis (battery) ground. If battery power is not found, replace the controller
and check the actuator and actuator wiring for grounds and shorts.
NOTE: Check wiring before replacing controller. Bad wiring might destroy
the new controller.
I
Check continuity across actuator wires. 2 ohms & 5 ohm should be
measured. Check the continuity of actuator wires to the case. The ohms
measured should be 1 M or greater. If these values are out of tolerance,
replace actuator.
II. Engine
doesn' t
change
speeds.
1. Incorrect engine
speed.
With the engine running, connect battery power to pin H. This will select
Run 2. If Run 2 is set a higher speed than Run 1 and the speed does not
change, replace the controller. Contact OEM for speed settings.
With the engine running, connect battery power to pin G. This will select
Run 3. If Run 3 is set higher than the previous speed and the speed does
not change, replace the controller. Contact OEM for speed settings.
L
With the engine running, connect battery power to pins G & H. This will
select Run 4. If Run 4 is set higher than the previous speed and the speed
does not change, replace the controller. Contact OEM for speed settings.