Testing The Wiring; Harness - Stihl MS 661 Manual

8.3.6

Testing the Wiring

Harness

– Carry out preparations, b 8.3.1
– Check contact and operation,
b 8.3.3
– Set Master Control lever
to STOP 0 and hold it there.
1
: Lift locking tab (arrow) and pull
off the flag terminal (1).
– Check the flag terminal,
disassemble and clean if
necessary, b 7.10
Testing ground connection
1
: Measure resistance between
terminal socket (1) with black
wire and screw (2) on control
unit.
Specified value: < 10 Ω.
MS 661, MS 661 C-M
2
: Measure resistance between
contact spring (1) and screw (2)
on control unit.
Specified value: < 10 Ω.
If the specified values are not
obtained
– Check wires for break and
replace wiring harness if
necessary, b 8.3.6
Checking wires between control
unit and diagnostic socket
– Connect test cable, b 16
2
1
: Measure resistance between
terminal socket (1) with red wire
and test cable's black plug (2).
Specified value: < 10 Ω.
1
1
: Measure resistance between
terminal socket (1) with black
wire and test cable's red plug (2).
Specified value: < 10 Ω.
If the specified values are not
obtained
– Check contact between terminal
socket on switch shaft and
contact spring.
– Check continuity between wires
and terminal sockets
– terminal sockets must be firmly
connected to the wires. If there
are problems with contact,
replace the wiring harness,
b 8.3.3, b 8.3.6
2
2
65