If the radiator fan relay is normal, check the wiring for continuity, using the wiring diagram in this section.
Special Tool - Hand Tester: 57001-1394
If the wiring is good, check the ECU for its ground and power supply (see ECU Power Supply Inspection in the Fuel System (DFI) chapter).
If the ground and power supply are good, replace the ECU (see ECU Removal/Installation in the Fuel System (DFI) chapter).
Radiator Fan Circuit

1. ECU
2. Fan Motor
3. Ignition Switch
4. Joint Connector F
5. Fuse Box 1
6. Ignition Fuse 15 A
7. Relay Box
8. Fan Relay
9. Frame Ground 3
10. Fuse Box 2
11. Fan Fuse 15 A
12. Starter Relay
13. Main Fuse 30 A
14. Battery
15. Engine Ground
Radiator Fan Relay Removal/InstallationCrankshaft Side Clearance Inspection
Insert a thickness gauge [A] between the thrust washer
[B] on the crankcase and the crank web [C] at the #3 main
journal to determine clearance.
If the clearance exceeds the service limit, replace the
thrust washers as a set and check the width of the crankshaft
#3 main journal.
Cra ...
Crankcase Splitting
Remove the engine (see Engine Removal in the Engine
Removal/Installation chapter).
Set the engine on a clean surface and hold the engine
steady while parts are being removed.
Remove:
Cylinder Head (see Cylinder Head Removal in the Engine
Top End chapter)
Starter Motor (see Starter M ...
Tail/Brake Light (LED) Removal/Installation
Remove:
Upper Seat Cover (see Seat Cover Removal in the
Frame chapter)
Disconnect the tail/brake light connector [A].
Remove:
Tail/Brake Light Mounting Screws [A]
Bolts [B] and Brackets [C]
Bolt [D]
Remove the tail/brake light [A].
Bring down the rear fender rea ...