Clarke ZE - Page 32

Page 32 of 41
Figure #31
The “INITIALIZATION PATTERN will flash. This is
normal. The continuous two (2) blink flash sequence
should turn off at this point.
Three (3) blinks – Engine Coolant Temperature
Sensor malfunction: Status lamps will flash three
times continuously on the Clarke instrument panel
and a “Low Engine Coolant Temperature” alarm will
be sent to the fire pump controller via circuit #312.
Cause:
Engine coolant temperature sensor circuit is open or
shorted.
Corrective Actions:
Verify wiring and connector plug at engine coolant
temperature sensor are secure. Sensor is located on
the rear of the cylinder head (Figure #32A).
Figure #32A – ZF6H engine models
On the Clarke instrument panel, operate the
“OVERSPEED RESET” switch for four (4) seconds
and release. (Refer to Figure #31).
The “INITIALIZATION PATTERN” will flash. This
is normal. The continuous three (3) blink flash
sequence should turn off at this point.
If problem still exists, replace engine coolant
temperature thermistor.
Five (5) blinks on instrument panel – Oil pressure
switch or Engine speed sensor (magnetic pick-up)
malfunction: Status lamps will flash five times
continuously on the Clarke instrument panel and a
“Low Engine Coolant Temperature” alarm will be
sent to the fire pump controller via circuit #312.
Cause:
Oil pressure switch failure or magnetic pick-up
failure.
Corrective Actions:
Oil Pressure switch check
Verify wiring and connector at engine oil pressure
switch are secure. Pressure switch is located on right
side of engine near the oil cooler (Figure #33).
With engine off, check continuity between the WK
terminal and engine ground. Note, do not disconnect
wire when performing this task.
If circuit is open, replace oil pressure switch.
After new switch is replaced: On the Clarke
instrument panel, operate the “OVERSPEED
RESET” switch for two (2) seconds and release.
(Refer to Figure #9)
The “INITIALIZATION PATTERN’ will flash. This
is normal. The continuous five (5) blink flash
sequence should turn off at this point.
If circuit is closed, the oil pressure switch is not
damaged and is working normally as expected.
Proceed to engine speed sensor check, below.