Thermoswitch
Disconnect negative battery cable. Remove thermoswitch, suspend switch and place a thermometer in container filled with water. Connect ohmmeter between thermoswitch terminal and base. Gradually heat water and check switch continuity. (Scheme 1) Switch is normally open. Continuity should not exist until temperature reaches more than 207°F (97°C). If continuity is not as specified, replace thermoswitch.
Scheme 1
Cooling Fan Relay
- To test relay, disconnect relay wiring harness connector. (Scheme 2)
- Check for continuity between fan relay terminals "A" and "C". (Scheme 3) Continuity should not exist. Check for continuity between terminals "B" and "D." Continuity should exist.
- Apply battery voltage between terminals "B" and "D", and check for continuity between terminals "A" and "C". Continuity should exist. If continuity is not as specified, replace relay. If relay is good, check fuse and wiring.
