OVM_FT-0113
9
Check Fans Is Lit (Red Light)
Check Fans Is Lit
(Red Light)
Check that air
filters are clean
and not obstructed
Obstruction exists
Not Obstructed
Clean/replace
filter(s) or
remove
obstruction
With air filters removed,
check that each fan is
drawing air
All 4 fans are OK
One fan is not OK
2 fans on the same
side are not OK
None of the four fans
are OK
Using the visual view
screen, check it the relay
board temperature is
below 120°F
Check that AC power
is at the fan
Check that AC power
is at the fans
Check for AC present
on relay board
connector J1
Relay board
temperature is
≥ 120°F
Check fan
light is on.
This is
normal
Repair/
replace
wiring as
necessary
Replace
the 2
non-working
fans
Replace
the fan
wiring
Plug in fans
Replace
relay board
Check relay
board to fan
wiring and repair
or replace
as needed
Replace the
non-working
fan
Replace
relay board
Replace the
cutoff switch
that has
continuity
Relay board
temperature is
below 120°F
Check continuity
of both thermal
cutoff switches
AC not OK on
relay board
connector J1
AC OK on
relay board
connector J1
Check wiring
from 10 amp
fuses, through
terminal blocks
TB3 & TB4 to
relay board
connector J1
No AC power
at the fans
AC power is
at the fans
Check that fans
are plugged in
AC power is
present at the
non-working fan
AC power is not
present at the
non-working fan
Fans are
plugged in
Fans are not
plugged in
Check for AC
present on relay
board connectors
J18–J21
AC OK on
relay board
connectors
AC not OK on
relay board
connectors
