Figure 9−4 Enscu Diagnostic Tree - 2 Long, 7 Short Led Code - Carrier VECTOR 6500 Operation & Service Manual

Replace ENSCU. Did you
find and correct the condition?
NO
System
Remove new ENSCU
OK
and re-install old
ENSCU back into
unit, ENSCU is not the
fault. Review results
of above tests with
your supervisor. If
necessary, go to the
beginning of
the tree & test again.
Figure 9−4 ENSCU Diagnostic Tree - 2 Long, 7 Short LED Code
62-11389
START HERE
With the Main Power
switch ON and the ENSCU
wire 13 removed from the
connector (connector
plugged in), check voltage
at ENSCU terminal 13. Is
NO
voltage 26 VDC or higher?
NOTE: With connector
unplugged, unit will not
start but will crank.
Check voltage while unit
is cranking.
YES
Starting at terminal
13 at the ENSCU,
check circuit for
induced voltage
creating the 26 VDC
signal.
Did you find and
correct the condition?
NO
Review results
of above tests
with your super
visor. If
necessary, go
to the
beginning of the
tree &
test again.
YES
NO
YES
System
OK
9−12
Check voltage output at
alternator. Is voltage 26
VDC or higher?
YES
Replace alternator.
Did you find and
correct the condition?
NO
Remove new
alternator and
re-install old
alternator back into
unit, alternator is not
the fault. Review
results of above
tests with your
supervisor. If
necessary, go to the
beginning of the
tree & test again.
YES
System
OK