14.7.2 Test Connections And Test Values - Stihl MS 661 Manual

14.7.2 Test Connections and Test Values

– The pin and socket connections
of the wires in the rear handle
must be disconnected to test the
individual components.
Component
Switch
Heating element in
rear handle
Heating element in
handlebar
1)
Pull out wire for this purpose
128
Ohmmeter
connection (use either
test lead)
Lead 1 Lead 2
Switch Switch
1)
terminal housing
Connector Connector
on wire on wire
from from
heating heating
element element
Connector Connector
on wire on wire
from from
handlebar handlebar
heating heating
element element
Resistance Ω
If faulty
Spec. Actual Cause
< 0.5 - Switch faulty
1.6 1.5 - 2.0 Heating element
OK
- Break in wire,
heating element
damaged
0 Short circuit –
damaged insulation
6.4 6.0...8.0 Heating element
OK
- Break in wire,
heating element
damaged
0 Short circuit –
damaged insulation
Remedy
Replace switch
Replace heating
element or
repair insulation
Install new
handlebar
Repair insulation
MS 661, MS 661 C-M