14.5.2 Test Connections And Test Values - Stihl MS 650 Manual

14.5.2 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
separately.
Component
Switch
Connector tags
Heating element in
rear handle
Heating element in
front handle
Generator
1)
Pull out wire for this purpose
MS 650, MS 660
Ohmmeter connection
(use either test lead)
Lead 1 Lead 2
Switch Switch
1)
terminal housing
Connector Ground
tags
Connector Connector
on wire on wire
from rear from rear
handle handle
heating heating
element element
Connector Ground
on wire
from front
handle
heating
element
Connector Ground
on red
wire
Resistance Ω If faulty
Spec. Actual Cause
< 0.5 - Switch faulty
0 > 1.0 Poor ground
connection
1.0 0.8...1.2 Heating element
OK
- Break in wire,
heating element
damaged
0 Short circuit –
damaged insulation
7.0 6.0...8.0 Heating element
OK
- Break in wire,
heating element
damaged
0 Short circuit –
damaged insulation
0.5 0.3...1.0 Generator OK
Remedy
Replace switch
Replace ground
wire
Install new heating
element or repair
insulation
Install new front
handle
Repair
insulation
101