Stihl 064 Service Manual page 64

STIHL 064, 066
9. ELECTRIC HANDLE
HEATING SYSTEM
9.1 Troubleshooting
Heating element in rear handle
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 from outside.
Important: The heating element in the rear
handle may fail as a result of overheating if
it is not bonded firmly in position without
creases.
There are two reasons for failures in the
heating system:
- A break in the circuit due to a faulty wire
or component.
- A short circuit resulting from damage to
the insulation.
To trace the cause of a fault:
- Remove the carburetor box cover, air filter
and handle molding.
- Separate the plug connection of wires
1 and 3.
Top:
Removing handle molding
Center:
Plug connections
1 = Generator wire
2 = Wire to front handle heating element
3 and 4 = Wires to rear handle heating
element Heater switch on "I"
- Clip the ohmmeter test leads to wires
1 and 3.
- Set the heater switch to "I".
Note: All electrical components of the
heating system are connected in series
with the ohmmeter.
If the system is intact, the ohmmeter
should indicate a value of around 2.5
in measuring range " x 1 ". If no
reading is obtained, there is a break in
the circuit. If the ohmmeter shows a
value of less than 2.5 , there is a short
circuit in one of the components.
In either case it is necessary to check
each component separately. The
generator wire remains disconnected
from the heating element during this
check.
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