1. Check the Fuses: This is the easiest and cheapest thing to check first. Consult your owner's manual to locate the fuse box (there might be more than one) and find the fuse(s) related to the radiator fan(s). They might be labeled, or you might need to use a multimeter to test continuity. Replace any blown fuses.
2. Check the Relays: Radiator fans often use relays to switch the higher current needed to run the fans. These relays are electrically controlled by the engine computer or other components. Find the relay(s) for the cooling fan(s) (again, consult your owner's manual), and try swapping them with known-good relays of the same amperage rating. If swapping fixes the problem, the original relay is faulty.
3. Check the Fan Motor(s): If fuses and relays are okay, the problem could be the fan motor itself. You can try bypassing the relay (carefully and temporarily, using jumper wires, only when the engine is OFF!) to see if the fan runs directly from power. *Warning:* This is dangerous if done improperly. If it works, the problem is likely the relay or its control circuit. If it does not work, the motor is likely bad.
4. Check the Fan Control Circuit: This is the most complex part and may require more advanced troubleshooting:
* Temperature Sensor: The engine's coolant temperature sensor tells the computer when to turn on the fans. A faulty sensor might not signal the computer that the engine is overheating.
* Cooling Fan Control Module (CFCM) or Engine Control Module (ECM): The ECM or a dedicated CFCM (if present) controls the fan relays. A faulty module would require diagnosis with a scan tool.
* Wiring: Check the wiring harness for any damage, corrosion, or loose connections between the temperature sensor, relay, fan motor, and the ECM/CFCM.
5. Low Coolant Level: While not directly causing the fan to not run, a very low coolant level can trigger an overheating situation where the fans *should* be running. Check your coolant level.
Important Notes:
* Safety First: Working with car electrical systems can be dangerous. Disconnect the battery negative terminal before working on any electrical components.
* Owner's Manual: Your owner's manual is your best friend for locating fuse boxes, relays, and other components.
* Professional Help: If you're not comfortable working on car electrical systems, it's best to take your vehicle to a qualified mechanic for diagnosis and repair. An overheating engine can cause serious damage.
Start with the simplest steps (fuses and relays), then progress to the more complex ones if necessary. Remember to always consult your owner's manual for specifics relating to your 1997 Chevy Malibu.
