Q: How to check and replace the Cooling Fan Assembly?A: To troubleshoot cooling system problems, if the engine overheats and the cooling fan is inactive, disconnect the fan motor's electrical connector, then test the fan by directly connecting it to the battery and ground; replace if necessary. If the radiator fan doesn't engage when the engine heats up, examine the fan relays, which might be faulty. Locate the relays in the engine compartment fuse/relay box (additional small relay box for 2007 and later models) and test them. If the relays are fine, assess the radiator fan switches, which regulate fan operation based on temperature. For 2003 and earlier models, utilize fan switches, while later models use Engine Coolant Temperature (ECT) sensors. Test switches using an ohmmeter and temperature continuity. In case of relay and fan switch confirmation, inspect wiring and connections to the fan motors, considering professional repair if needed. For replacement, disconnect the battery, secure the vehicle, remove the lower splash shield, and drain the cooling system if needed. Proceed by removing the radiator cover and coolant reservoir, detaching upper radiator hose, disconnecting fan electrical connectors and harnesses, unbolting the fan shroud assembly, and finally removing the fan and motor. Installation is the reverse of removal. For cooling fan switches (2003 and earlier), disconnect and unscrew switches, then install new sealing rings lubricated with coolant during reassembly. Refill the cooling system, reconnect the battery, and verify proper fan operation.