1. Visual Inspection (Easiest):
* Turn on the AC: With the engine running, turn on your air conditioning. The radiator fans *should* turn on almost immediately. This is the most common trigger for the fans.
* Check for High Engine Temperature: Let the engine run until it reaches normal operating temperature. The fans should turn on automatically once the coolant temperature reaches a certain point. You can monitor this with the temperature gauge on your dashboard. If it's climbing into the red zone and the fans aren't running, that's a serious problem.
* Inspect the Fans Directly: Carefully look at the radiator fans. Are they spinning? You may need to have someone else turn on the AC or let the engine warm up while you watch. Be cautious around hot engine components.
2. Listening for the Fans (Easy):
With the engine running and either the AC on or the engine at operating temperature, listen carefully. The fans will make a distinct whirring sound.
3. Checking the Fan Relays (Intermediate):
* Locate the Relays: Consult your Impala's owner's manual or an online repair manual to locate the radiator fan relays. They are usually found in the underhood fuse box.
* Swap Relays: If you have a spare relay of the same type and amperage rating, swap it with one of the radiator fan relays. If the fans work with the swapped relay, the original relay is faulty. This helps to isolate if the problem is the relay or the fans themselves.
4. Testing the Fan Motors Directly (Advanced):
This requires more mechanical knowledge and tools. It involves disconnecting the fan motors and using a multimeter to test if they are receiving power and if the motor itself is functioning. This is best left to someone with experience.
Important Considerations:
* Low Coolant: If your coolant is low, your car may overheat, and the fans may not engage. Check your coolant level before proceeding.
* Safety: Always turn the engine off and allow it to cool down before working on any components in the engine bay.
If you've checked these steps and the fans still aren't working, it's recommended to take your Impala to a qualified mechanic for diagnosis and repair. A non-functional cooling fan can cause serious engine damage due to overheating.
