Why is the air conditioning not cooling properly after engine warms up?

Home > Gari Forums > Suzuki Forums > Suzuki Wagon R Forums > Suzuki Wagon R Sensor Issues Forums

Why is the air conditioning not cooling properly after engine warms up?

In my Suzuki Wagon R, the AC works fine when I first start the engine, but after 10–15 minutes, the cooling weakens. Someone told me this could be a sensor issue, not just gas o r compressor. Could a faulty engine temperature sensor o r AC pressure switch cause this?

Gari Specialist asked on 30 May 2025 13:37:24 pm

1 Answer

27 views |

Gari Master - on 30 May 2025 13:47:29 pm

AC performance that degrades after warming up can sometimes be linked to sensor faults. Key possibilities include:

Engine Coolant Temperature Sensor: If it reports overheating incorrectly, the ECU may reduce load on the engine by cutting AC power.

AC Pressure Switch/Sensor: This monitors refrigerant pressure. If faulty, it may cause the compressor to disengage prematurely.

Ambient Temperature Sensor: Some systems adjust cooling performance based on external temperature if this sensor fails, the AC may behave abnormally.

Fix:
Check if the AC compressor is turning off when the cooling fades. If so, scan the ECU for sensor data while the engine is running. If the temperature sensor reports high values incorrectly, replace it. A technician can also test refrigerant pressure and the AC relay.