Yamaha YZF-R125 Service Manual: Checking the turn signal relay
1. Check:
Turn signal relay input voltage
Out of specification →The wiring circuit
from
the main switch to the turn signal relay coupler
is faulty and must be repaired.
a. Connect the pocket tester (DC 20 V) to the
turn signal relay terminal as shown.
- Positive tester probe 
brown "1"
- Negative tester probe 
ground 
b. Set the main switch to "ON".
c. Measure the turn signal relay input voltage.
2. Check:
Turn signal relay output voltage
Out of specification Replace.
a. Connect the pocket tester (DC 20 V) to the
turn signal relay terminal as shown. 
Positive tester probe
brown/white "1"
Negative tester probe
ground
b. Set the main switch to "ON".
c. Measure the turn signal relay output voltage.
Checking the relays
Check each switch for continuity with the pocket
tester. If the continuity reading is incorrect, replace
the relay.
1. Disconnect the relay from the wire harness.
2. Connect the pocket tester ( ...
Checking the diode
1. Check:
Diode
Out of specification Replace.
NOTE:
The pocket tester or the analog pocket tester
readings are shown in the following table.
a. Disconnect the diode from the wire harness.
...
Other materials:
Checking the fuses
The following procedure applies to all of the fuses.
CAUTION:To avoid a short circuit, always turn the
main
switch to "OFF" when checking or replacing
a fuse.
1. Remove:
Rider seat
Refer to "GENERAL CHASSIS" on page 4-1.
2. Check:
Fuse
a. Connect the pocket te ...
Checking the fid (fast idle solenoid)
1. Disconnect:
FID (fast idle solenoid) coupler
2. Check:
FID (fast idle solenoid) resistance
a. Disconnect the FID (fast idle solenoid) coupler
from the FID.
b. Connect the pocket tester ( × 10)
to the terminals
of the FID (fast idle solenoid).
Positive tester probe ...
Checking the drive sprocket
1. Check:
Drive sprocket
More than 1/4 tooth "a" wear
Replace the
drive chain sprockets as a set.
Bent teeth Replace the drive
chain sprockets
as a set.
b. Correct
1. Drive chain roller
2. Drive chain sprocket
Checking the rear wheel sprocket
Refer to "CHECKING AND R ...