Engine Overheating Diagnosis

Fig. 3 Cooling System Faults:

Refer to Fig. 3 for diagnosis procedure.

1. Fuse or relay defective.
2. Electro-magnetic engine fan coolant temperature switch faulty.
3. Electric cooling fan not operating:
a. When compressor is engaged.
b. When engine coolant temperature switch closes.
4. Electro magnetic engine fan not operating when engine coolant temperature switch closes.
5. Incorrect radiator. Vehicles with A/C should have copper core radiator.
6. Missing fan cowling or deflectors.
7. Radiator cap of insufficient pressure rating. Should be 14-15 psi.
8. Cooling system does not have correct anti-freeze mix.