Diagnosis

Fig. 1 Fan motor connector terminal identification:

FAN MOTOR

1. Disconnect electrical connector from fan motor.
2. Apply battery voltage to terminals 2 and 3 of fan motor connector, Fig. 1.
3. Fan motor should activate. If motor fails to activate, it should be replaced.




THERMOSENSOR

1. Immerse sensor in hot water up to mounting threads, then connect one lead of a suitable ohmmeter to hex nut and other lead to sensor terminal. Observe ohmmeter.
2. Continuity should exist with water temperature between 180-190°F., and should not exist below stated temperatures.
3. Replace thermosensor if other than specified results are obtained.

Fig. 2 Fan relay terminal identification:

FAN RELAY

1. With no voltage applied to relay terminals, check continuity between terminals with suitable ohmmeter. Continuity should only exist between terminals 2 and 4, Fig. 2.
2. Apply battery voltage to terminals 2 (positive) and 4 (negative), then check continuity between terminals. Continuity should only exist between terminals 1 and 3.
3. If other than specified results are obtained, replace relay.