Heating Element With Thermostatic Switch; Handle Heating System; Troubleshooting - Stihl MS 440 Service Manual

13.2 Heating element with
thermostatic switch
2
1
– Remove the heating element –
b 12.2.1
: Unplug the two leads (1+2).
The plug and socket connection
must not be bent or kinked during
removal or installation, otherwise
the parts may break.
Reassemble in the reverse
sequence.
Check that the plug connection lies
flat after fitting the baffle.
MS 440, MS 440 C
14.

Handle Heating System

14.1

Troubleshooting

The entire handle heating system is
maintenance-free and subject to
practically no wear. Faults in the
generator, heating elements and
wiring are generally caused by
mechanical damage.
There are two reasons for failures in
the heating system:
1. A break in the circuit due to a
faulty wire or component.
2. A short circuit resulting from
damage to the insulation.
If the affixed heating element in the
rear handle does not adhere firmly
at all points and without creasing, it
may also fail due to overheating.
Tracing the cause of a fault
– Remove the interlock lever –
b 10.2
: Remove the protective tubing
(arrow) over the plug connecting
the lead from the generator to the
handle heating element.
: Unplug the two leads.
: Set the heater switch (arrow) to
position "#".
– Set ohmmeter to "Ω".
81