How do I test an A/C condenser fan?
Short answer: Check whether the fan runs when the A/C is on and head pressure rises, then test the fan's power, ground and relay or control module, and use a scan tool to command it if supported.
The condenser fan pulls air across the condenser to remove heat. If it does not run, head pressure climbs, cooling suffers at idle and in traffic, and the compressor may shut off on high pressure. Many vehicles share the fan with engine cooling, so overheating at idle can be a related symptom.
Turn on the A/C and watch the fan. If it does not run, check for codes and use a scan tool to command it. Many vehicles control fan speed through a module or pulse width signal rather than a simple relay, so check service information for how the circuit works. Test power and ground at the fan connector under load, since a corroded connection may pass a meter test but fail when the motor draws current. A current probe on the fan feed can reveal a dragging motor.
Keep hands, tools and clothing away from the fan, since it can start without warning even with the engine off.
Tools used for this job
General guidance only. Follow the vehicle and tool manufacturer's procedures, and confirm vehicle coverage on the tool maker's list before buying.