There are several switches involved in an ac system . There is a high pressure switch that turns off the compressor if the head pressure is too high (blocked system-excessive gas qty) and a low pressure switch that switches off the compressor when there is insufficient gas -(leaking system)/ Next some systems do not work unless the blower and the ac switch are both on ( prevents ice forming on the evaporator coils from lack of air flow ). That is the electrical side of things . Next there is a TX valve that allows the liquid refrigerant to become gas in the evaporator ( producing the cold air) that can become blocked . There is a thermostat that is attached to the evaporator fins that will shut off the ac compressor when the cabin temperature has been reached. Next there is an air/dryer accumulator that can become blocked from moisture and dirty oil that will affect the operation. Well that is all the points that can cause problems.
How does it work . The system is full of refrigerant gas that boils off at a very low ambient temperature . The compressor compresses this gas and turns it into a liquid refrigerant in the condenser (In front of the radiator ) This liquid is pumped to the TX valve which releases the liquid into the evaporator coil and as this area is in vacuum from the compressor sucking the gas ,the liquid going from a liquid into a vacuum boils off from the heat in the car . This cools the air in the car . The gas is then sucked back to the compressor where it is again converted back to a liquid . As you can see ,any items that are not working properly will cause problems because the circulation of the gas has to follow a set procedure or the compressor will shut down. Best advice is -if you having ac problems then take it to an accredited ac specialist and have the system tested for gas and leaks.
Apr 22, 2014 |
1999 Chevrolet Silverado 1500