Your vehicular air conditioning must contend with a much more hostile environment than your home unit. Auto air conditioning systems are mostly under the hood where it is subject to high heat from the engine operation. Heat affects the hoses of the system, at least those under the hood. As we negotiate the city streets and rural roads the automotive A/C system is subject to shocks and vibrations not encountered in the home system.
Car AC Working Diagram
The auto A/C works like the one on your home. There is a compressor run by the engine. The compressor pumps refrigerant to the condenser coils usually mounted ahead of the radiator in the front. The refrigerant enters as a gas, gives up heat to the air flowing through the condenser, turns to a liquid and is transported via high pressure hose to the evaporator inside the dash, and a fan moves air across the cooling fins, giving up heat that evaporates the refrigerant back to a gas then passes via a return hose to the compressor.
Leaking AC Compressor for Car
The A/C compressor is a key component to the auto air conditioning system. One of the most common problems is leaks. The seals are subject to engine generated heat and vibration fail and release refrigerant. The compressor is a mechanical component subject to wear. Friction is high and metal particles are introduced into the compressor further compromising its operation.
Auto AC Accumulator & Drier Leak
Another component is the called the accumulator/drier that collects moisture that is entrapped in the system thereby protecting the compressor. Leaks impact the accumulator/drier by introducing more moisture into the system than it can handle. This can lead to over saturation which can damage the compressor. This component is mounted between the evaporator and the compressor.
Orifice Tube & Expansion Valve Pressure in Auto AC
These parts regulate the flow of refrigerant. An A/C gauge attached by the technician will show irregular pressure readings. Too low on the low-pressure or gas side is as bad as the too high on the high-pressure liquid side. This put stress on the compressor leading to premature failure. Replacement of the orifice tube/expansion valve is the solution. This is mounted on the high pressure side between the condenser and the evaporator.
Damaged Universal Auto A/C Condenser
The condenser, as mentioned above is mounted in front of the radiator. It looks like a radiator, and as it sits in front of the coolant system it is subject to damage from road debris. Small stones, airborne debris and insects all contrive to compromise the efficiency of the condenser. Leaks and entrapped internal particles are the primary points of failure. As a hot the air passing through the condenser is hotter than ambient air temperatures. The engine cooling system must be designed to accommodate these higher temperatures to cool the engine.
Car AC Evaporator Leak
The evaporator is another radiator looking contraption mounted either in a housing on the engine side of the firewall or just under the dash. Inside air is recirculated through the coils to transfer the air heat to refrigerant that then expands from a liquid to a gas. Low pressure on the low side would indicate a leak in the evaporator or connecting A/C lines.
Auto Air Conditioning Electromagnetic Clutch Wear
Other points of failure are the electromagnetic clutch on the compressor. This uses magnetic fields created by the flow of electrical power to engage and lock the clutch. It must cycle on and off to accommodate temperature settings. It does wear out.
Slipping Auto AC Serpentine or Other Compressor Belt
The last thing on our list is the belt that drives the compressor. On modern engines there is a single point of failure as the newer vehicles use a serpentine belt to drive all the engine accessories like the A/C compressor of course. Others are the power steering, on some the emission air pump, the engine water pump and alternator that recharges the electrical and battery system.