Why does the temperature rise when the air conditioner is turned on?
3 Answers
The main reasons for the temperature rising when the air conditioner is turned on are as follows: 1. Electric fan malfunction: Normally, the electric fan has two gears, a low-speed gear and a high-speed gear. The high-speed gear usually operates when the air conditioning pressure is too high or when the engine's water temperature reaches 103 degrees Celsius. 2. Insufficient opening of the thermostat: If the thermostat's opening is too small at normal temperatures, it can slow down the circulation speed of the engine's cooling water, leading to high water temperature at low speeds. 3. Water pump idling: If the water pump shaft is cracked, it can cause idling when the water temperature is high, resulting in elevated water temperature. 4. Wiring issues: Poor grounding of the ground wire near the battery or the engine's water temperature sensor can easily cause the water temperature gauge to indicate a higher temperature, also known as a false high.
Having worked in an auto repair shop for over a decade, I can tell you that the primary cause of overheating when the AC is turned on lies in the increased load on the cooling system. The activation of the AC compressor adds extra strain to the engine. If the cooling fan isn't functioning, or if there's insufficient coolant or a blockage in the pipes, heat can't dissipate properly, causing the water temperature to spike immediately. Another possibility is that the AC condenser is clogged with dust, reducing its cooling efficiency. My advice is to first check if the fan is running: when the car is started without the AC on, the fan should activate. If it doesn't, inspect the fuses or relays. Additionally, a worn-out water pump or a stuck thermostat can also contribute to the problem. Remember to change the coolant regularly and perform a cleaning before the summer heat hits. Neglecting this issue can damage the engine, so it's best to get it checked by a professional shop as soon as possible.
As a seasoned long-distance driver, I've encountered this issue several times. When the AC is turned on, the water temperature rises, usually due to a stuck fan or insufficient coolant. Don't panic—first, stop and check if the coolant reservoir is full, then start the vehicle to see if the fan is spinning. If it's not, it could be an electrical issue or a broken fan. In my case, it was a burnt-out fan relay, and replacing it fixed the problem. Also, make sure the radiator fins are clean, as dust buildup can significantly reduce cooling efficiency. If all else fails, a faulty water pump or thermostat could be the culprit, so it's best to have a trusted mechanic inspect it. Water temperature issues affect engine health, so don't take them lightly.
