Husqvarna PT26D Workshop Manual page 127

A breakage on the cable between J1 and the
analogue sensor on the thermostat housing
results in theemergency glow plug heating
function activating with a fixed heating time.
Caution: only with an open circuit, if there is
another fault on the sensor so that glow plug
heating does not work the connector can be
disconnected from the sensor and run with
this emergency glow plug heating time. The
time is temperature independent and about
half of the max. time. Check the sensor with
an ohmmeter 0.9 - 1 at room temperature.
With regard to the circuit that activates the
starter motor, proceed in the same way as for
the glow plug heating circuit. A fault in the
glow plug heating circuit can prevent the
starter motor from working. Turn the ignition
key back to glow plug heating and the start
position within 3 seconds. If the starter motor
works, look for the fault in the glow plug heat-
ing circuit.
Cooling fan
A fault in the circuit to the cooling fan's soft
start function can mean that the fan does not
start. Check the cables between the circuit
board and connector on the fan for a short
circuit or open circuit. Now connect an exter-
nal battery to the connector and test run the
fan. Measure the current with an ammeter. If
the fan works normally and the current after
start does not exceed 12 A, replace the cir-
cuit board.
Oil pressure
A short circuited oil pressure sensor means
the engine will stop directly after starting. Dis-
connect the cable from the sensor and test
start. If the engine now starts it is either the
sensor that is malfunctioning or the oil pres-
sure is too low. A sensor with an internal
mechanical fault can cause engine problems,
the engine can stop or run unevenly.
126
English-
TROUBLE SHOOTING
Disconnecting oil pressure contact
Resistance test analogue sensor
Measuring current to cooling fan
8043-177
A
8043-183
8043-176