Operation CHARM: Car repair manuals for everyone.

Exercising System

EXERCISE SYSTEM
An important fact most owners ignore is that A/C units must be used periodically. Manufacturers caution that when the air conditioner is not used regularly, particularly during cold months, it should be turned on for a few minutes once every two or three weeks while the engine is running. This keeps the system in good operating condition.

Checking out the system for the effects of insufficient use before the onset of summer is one of the most important aspects of A/C servicing. First clean out the condenser core, mounted in all cases at the front of the radiator. All obstructions, such as leaves, bugs, and dirt, must be removed, as they will reduce heat transfer and impair the efficiency of the system. Make sure the space between the condenser and the radiator also is free of foreign matter.

Make certain the evaporator water drain is open. Certain systems have two evaporators, one in the engine compartment and one toward the rear of the vehicle. The evaporator cools and dehumidifies the air before it enters the passenger compartment; there, the refrigerant is changed from a liquid to a vapor. As the core cools the air, moisture condenses on it but is prevented from collecting in the evaporator by the water drain.