Diesel Data: Automotive Repair

On-Vehicle Inspection

ON-VEHICLE INSPECTION

Low Coolant Temperature [Below 83°C (181°F)]





1. TURN IGNITION SWITCH "ON"
- Check that the fan does not rotate.
- If it does, check the fan relay and temperature switch, and check for a separated connector or severed wire between the relay and temperature switch.








2. DISCONNECT TEMPERATURE SWITCH CONNECTOR
- Check that the fan rotates.
- If it does not, check the fan relay, fan motor, ignition relay and fuse, and check for a short circuit between the fan relay and temperature switch.

3. CONNECT TEMPERATURE SWITCH CONNECTOR

High Coolant Temperature [Above 93°C (199°F)]

4. START ENGINE




- Raise engine coolant to above 93°C (199°F).
- Confirm that the fan rotates.
- If it doesn't, replace the temperature switch.