Yamaha XT660R Service Manual page 433

EAS00809
4. Radiator fan motor
• Disconnect the radiator fan motor coupler
from the wire harness.
• Connect the battery (DC 12 V) as shown.
Positive battery lead → red 1
Negative battery lead → black 2
• Does the radiator fan motor turn?
YES
NO
The radiator fan
motor is faulty and
must be replaced.
COOLING SYSTEM
5. Radiator fan motor relay
• Disconnect the radiator fan motor relay
from the wire harness.
• Connect the pocket tester (Ω × 1) and bat-
tery (DC 12 V) to the radiator fan motor ter-
minal as shown.
• Check the radiator fan motor for continuity.
Battery positive terminal → red/white 1
Battery negative terminal →
Positive tester probe → brown 3
Negative tester probe → blue 4
G/Y
L
Br
• Does the radiator fan motor relay have con-
tinuity between brown and blue?
EAS00813
6. Wiring
• Check the entire cooling system's wiring.
Refer to "CIRCUIT DIAGRAM".
• Is the cooling system's wiring properly
connected and without defects?
Replace the ECU.
8 - 51
ELEC
green/yellow 2
+
R/W
YES
Replace the radiator
fan motor relay.
YES
Properly connect or
repair the
system's wiring.
– +
NO
NO
cooling