Quick answer
Use this topic when the search intent is cooling fan relay wiring diagram and the repair needs exact circuit context, connector paths, fuse or relay feeds, module commands, and ground checks before parts are replaced.
Start with the guide, then use the matching catalog link to narrow by year, make, model, and system so the customer lands on the most relevant product page.
Cooling fan faults need command and load-side testing
A fan that never turns on, runs all the time, works only with A/C, or runs at the wrong speed can be caused by fuse feed, relay contacts, relay command, fan motor current, temperature sensor input, PCM logic, or ground resistance.
The wiring diagram separates the high-current fan path from the low-current command path so the technician can test the circuit without guessing.
A/C and engine cooling circuits often overlap
Many vehicles command the radiator fan for both engine temperature and A/C pressure. That means a cooling fan fault may require engine performance and air conditioning diagrams together.
The exact diagram shows whether the vehicle uses one fan, two fans, fan speed relays, a resistor, a fan control module, or pulse-width modulation.
How to use this topic
Search the intent
Start with cooling fan relay wiring diagram when the symptom needs exact circuit context.
Choose the vehicle
Narrow the catalog by year, make, model, and system before purchasing.
Verify before repair
Use the diagram with meter testing, connector inspection, and safe service procedures.
Questions technicians ask
Why does my cooling fan run when the A/C is on but not when the engine is hot?
The A/C request and engine temperature command can use different module inputs or control logic. The diagram helps confirm which side is missing command.
Can a cooling fan relay click and still fail?
Yes. A relay can click while the load contacts are burned, high resistance, or missing feed power under load.