Initial Inspection and Diagnostic Overview

1. Verify customer concern by running the engine (6007).
2. Visually inspect the following components of the engine cooling system:

MECHANICAL
^ Stuck or binding electric cooling fan
^ Damaged radiator, radiator cap, radiator hoses
^ Damaged radiator draincock
^ Improperly mounted electric cooling fan or fan shroud
^ Damaged heater core
^ Damaged water thermostat
^ Coolant level

ELECTRICAL
^ Blown fuse(s):
- 10A RLY COIL
- 65A RAD FAN
^ Damage to relays
^ Damage to wiring harness
^ Loose or corroded connections
^ Damaged electric cooling fan

3. Check the coolant level and condition.
4. Check the water thermostat operation. Component Tests and General Diagnostics
5. Check the electric cooling fan, fan blade (8600), and fan shroud for damage and proper mounting.
6. Check the radiator hoses for cracking, bulging, soft spots, or hardness.
7. If fault is not visually evident, determine the symptom and proceed to Diagnosis By symptom.