DR-15B Radiator Fan Relay Control Circuit

1. Turn ignition switch Off, then connect a voltmeter between terminal 21 of logic module red connector and ground.
2. Turn ignition switch to Run position.
3. If voltmeter indicates voltage is within 1 volt of battery voltage, replace logic module.
CAUTION: Before replacing the logic module make sure the terminal in cavity No. 21 is not crushed so that it cannot touch the logic module pin.
4. If voltmeter indicates no voltage, repair open circuit in wire to radiator fan relay from terminal No. 21.