What Causes Intermittent Cooling in Car Air Conditioning?
3 Answers
Intermittent cooling in car air conditioning may be caused by issues with the air conditioning heat dissipation, blower performance, or blower resistor. Below are the specific details: 1. Air conditioning heat dissipation: Inspect the surface of the air conditioning condenser for any debris that may affect heat dissipation. Otherwise, the air conditioning compressor may shut down due to excessive temperature, leading to the aforementioned poor cooling effect and temperature sensation. 2. Blower performance: Conduct a performance check on the air conditioning blower. The method involves dismantling the blower and rotating the fan blades to check for any resistance. If resistance is found, replace the blower. 3. Blower resistor: If the blower resistor is malfunctioning, it can also cause the aforementioned phenomenon. A common case is normal performance at high fan speeds but poor performance at low speeds. If this is the issue, replace the resistor.
Last year when I was driving my old car, I encountered an issue where the A/C cooling was intermittent. After pondering for a while, I figured it out. Most likely it was due to insufficient refrigerant—there might have been a minor leak in the system. When the refrigerant was nearly depleted, the pressure became unstable, causing the A/C to act up. Then there's the compressor clutch—if it had poor contact or was worn out, it couldn’t effectively drive the refrigerant cycle, especially during traffic jams when it was prone to failure. Additionally, if the evaporator’s filter was too dirty or clogged, the airflow would fluctuate, leading to inconsistent cooling performance. I tried checking the refrigerant pressure gauge myself, and the needle was jumping erratically. Eventually, I took it to the shop, and the mechanic said the condenser fins were clogged with dust—a simple cleaning fixed it. Remember to regularly clean the filters and inspect the lines during maintenance to avoid suffering from the heat on the road.
When repairing cars, we often encounter issues with erratic air conditioning cooling. Key areas to check include: the condenser surface being clogged with leaves and dust, leading to insufficient heat dissipation and intermittent AC failure; aging seals in the refrigerant lines causing leaks, low refrigerant levels, and weak cooling due to inadequate pressure; or faulty pressure switches or temperature sensors misjudging temperatures, causing the compressor to start and stop randomly. I recommend first rinsing the condenser fins with a water gun to see if cooling stabilizes. If that doesn’t work, use a pressure gauge to check for significant fluctuations in high and low-side pressure values. Oxidized or loose electrical connectors could also be the culprit—try tightening them. Ignoring this issue can damage the compressor, so it’s best to diagnose and fix it early for peace of mind.
