Yamaha YZF-R125 Service Manual: Checking the radiator fan motor

1. Check:

  • Radiator fan motor Faulty/rough movement → Replace.

a. Disconnect the radiator fan motor coupler from the wire harness.

b. Connect the battery (DC 12 V) as shown.

  • Positive tester probe → blue "1"
  • Negative tester probe → black "2"

Checking the radiator fan motor


c. Measure the radiator fan motor movement.

    Checking the speed sensor
    1. Check: Speed sensor output voltage Out of specification → Replace. a. Connect the pocket tester (DC 20 V) to the speed sensor coupler (wire harness end) as shown. Positive tester pro ...

    Checking the coolant temperature sensor
    1. Remove: Coolant temperature sensor WARNING Handle the coolant temperature sensor with special care. Never subject the coolant temperature sensor to strong shocks. If t ...

    Other materials:

    Checking the cylinder head breather hose
    1. Remove: Left side panel Refer to "GENERAL CHASSIS" on page 4-1. 2. Check: Cylinder head breather hose "1" Cracks/damage → Replace. Loose connection → Connect properly. CAUTION:Make sure the cylinder head breather hose is routed correctly. ...

    Checking the fuel pressure
    1. Check: Pressure regulator operation a. Remove the fuel hose connector cover "1" and disconnect the fuel hose "2" from the fuel pump. CAUTION:Although the fuel has been removed from the fuel tank, be careful when removing the fuel hose, since there may be fuel remaining i ...

    Checking the ignition coil
    1. Check: Primary coil resistance Out of specification  Replace. a. Disconnect the ignition coil connectors from the ignition coil terminals. b. Connect the pocket tester ( × 1) to the ignition coil as shown. Positive tester probe red/white "1" Negative tester probe orange ...

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