Common Vehicle Air Conditioning Problems

Troubleshooting you Car’s Air Conditioning (A/C) System

This summer’s record breaking temperatures have been great for beachgoers, cottagers and evening BBQs. However, if you have been driving your vehicle during this heat wave and your air conditioning system has stopped blowing cold air you have no doubt experienced a very hot and uncomfortable drive.

It is not uncommon during the summer months that the inside temperature of your car can easily reach upwards of 50C .

Maintaining a comfortable temperature inside your car is dependent on proper maintenance of your car’s A/C system.

How does you’re A/C System Work?

Your heater and air conditioner has three functions; cool the interior of your car down during the summer, heat the interior up and defrost the windshield in the winter. All three modes work together as a climate control system. A main computer that sits in the dash and also houses the controls for the mode and temperature settings controls this system.

An air conditioner lowers the inside temperature of your vehicle. It also cools, dries, and cleans the air by forcing the warmer air to release outside. If moisture or debris contaminates the air conditioner installed in your car, it will fail to cool the interior of your vehicle.

There are several key components of your A/C system that are electronically controlled and all need to be operating efficiently to remove the heat and moisture from the inside of your car. They include:

  • Compressor
  • Evaporator
  • Condenser
  • Pressurized refrigerant
  • Valves and hoses


Let’s start with the refrigerant (r134a) inside the system. This particular refrigerant was specifically created for the automotive industry sometime in the late 1980’s which is slightly different than home or industrial refrigerant applications. Some refer to this refrigerant as “Freon”.

The refrigerant or “Freon” is part fluid and part gas and is held under pressure inside the system. When the system is not running properly the refrigerant remains a gas under low pressure. This is usually a result of a system leak or malfunction of one of the system’s key components.

Think of a can of hairspray. The chemical reaction is similar to when you release the content, which is under pressure (propellant and product). When released, the can usually will become cold. The difference of course being that your A/C system remains under pressure and recycles/recovers the gas back through the evaporator to maintain the constant pressure and long term use of the system.

Although A/C systems generally operate similarly, every car manufacturer has a slightly different way of achieving the same result.

Common Air Conditioning Problems

For the A/C system to work efficiently and be ready for the hot weather and summer driving conditions, it needs to be free from leaks so that the refrigerant remains under pressure in the system. Although A/C systems are generally resistant to leaks and contamination, they are not leak–proof. Over time, contamination or leaks can appear and affect the cooling performance of your car A/C system.

In fact, the most common cause of inadequate cooling is when the refrigerant leaks through worn seals and o–rings, loose fittings and connections.

To make sure all parts and components of your A/C system work properly, we recommend scheduling your annual auto air conditioning service appointment at the beginning of the warm season. Your GB Autos advisor can recommend an A/C Performance Check to test for any worn hoses or seals, leaks or contamination — as well as help make sure your vehicle is ready for warmer weather.