8 Reasons Why Your Car’s A/C Is Not Blowing Cold Air
Air conditioning combats summer’s scorching heat during drives. But like any mechanical system, a vehicle’s A/C is prone to occasional malfunction, at the hands of individual component failure. Read on to learn about the most common causes of a car A/C not blowing cold air anymore and how much it’s going to cost to fix it.
Causes of a Car AC Not Blowing Cold Air
The following are several of the most common causes behind inefficient A/C system operation and cooling.
1) Low Refrigerant
Low refrigerant is by far the single most common cause of poor A/C cooling. This low refrigerant level is often caused by a previously undiscovered leak within the system. In any event, the offending leak should be located and repaired as necessary, prior to system recharging.
2) Excess Refrigerant
While not as common as a low refrigerant condition, an A/C system’s efficiency can be stifled by excessive pressures. These higher than average pressures are often caused by system overcharging.
This generally occurs when a motorist attempts to introduce additional refrigerant into their vehicle’s A/C system, with the assistance of an at-home charging kit.
3) System Restrictions
Restrictions within the A/C system can also serve as the root cause behind poor cooling. A restriction stifles refrigerant flow, often leading to inadvertent variances in system pressures. As a result, cooling often suffers quite dramatically.
4) Air/Moisture Contamination
A vehicle’s A/C system must be free of air/moisture contamination in order to operate at peak efficiency. Even the smallest amount of air/moisture will cause erratic pressures within an A/C system.
Air is often inadvertently introduced into such a system, during the use of an at-home charging kit. Excess moisture can also damage the desiccant found within the system’s receiver/drier or accumulator.
5) Damaged Compressor
A compressor, which pressurizes an A/C system’s refrigerant, can quickly fail if starved for oil. When this occurs, all cooling ceases on the spot, and temperatures within a car’s cabin begin to rise. One is also advised to flush the remainder of the A/C system, after experiencing an internal A/C compressor failure.
6) Clutch Failure
An A/C compressor relies upon the use of a clutch, which engages upon command to drive the rest of the unit’s internal components. This clutch is magnetically actuated and is released back into the free-wheel position when all power is withdrawn. When an A/C clutch fails, engagement of the system’s compressor will become impossible.
7) Faulty Cooling Fan
Cooling efficiency can also suffer at the hands of an non-operational condenser fan. The condenser requires adequate airflow at all times, to keep high side system pressures in check. If your vehicle is not blowing cold air when idling, yet cools as designed when accelerating, a faulty cooling fan is almost always to blame.
8) Malfunctioning Sensors
If any of an A/C system’s numerous sensors were to fail, the operation would be adversely affected. The vehicle’s computer would face significant difficulty when attempting to determine correct compressor clutch duty cycles.
