You expect your car’s air conditioning system to deliver cool air on those too hot to handle days. At some point, however, a problem may emerge, one that could challenge your abilities. Air conditioning repair is not always a simple do-it-yourself project. Here’s how to know when to DIY or trust the job to the experts.
Rule Out the Easy Problems
What’s keeping cold air from flowing from your air conditioning system? Before you worry that either the compressor, evaporator or the condenser is the problem, consider the easy issue first. Set your air conditioner to “fresh air” and place it on its highest setting.
First, if air isn’t flowing, a fuse may have blown. Locate the fuse box, with the help of your owner’s manual, determine which fuse supplies electricity to the air conditioning, and replace it if the fuse has blown.
Second, if the fuse is OK and air is blowing, but you sense an obstruction or detect an odd smell, then locate the cabin air filter. Cabin air filters are routinely placed in the glove box, beneath the dashboard or under the hood and adjacent to the firewall. A clogged or dirty air filter can impede air flow and contribute a foul odor but is an easy replacement.
Third, if air is flowing, but you’re hearing an odd sound coming from the vents, then your compressor may need replacing. Before you delve into the car’s air conditioning system, lift the hood and inspect the area around the windshield cowling. Any build up of leaves, sticks and road debris near the air intakes can impede air flow, contribute foul odors, or both. Try removing the blockages and retesting the system.
Fourth, examine the AC condenser. Look at the front of the AC condenser, typically located immediately behind the radiator. A build up of leaves and dirt can impede air flow, therefore, clean the area and try the AC system again.
Consider the Intermediate Problems
You’ve ruled out the easiest problems, now it’s time to get under the hood to discover what’s really going on.
Low refrigerant can cause AC problems. Leaks are difficult to detect as the R-134a refrigerant used produces gas, not liquid. Special refrigerant detecting dyes and devices can find leaks. Any oil & dye injector kit will get the job done.
If the refrigerant is low, invest in an AC Recharge R-134 kit. Each kit comes with refrigerant, gauge and instructions to help you put in the right amount of refrigerant.
Onto the Hard Stuff
If your air conditioner still doesn’t work after investigating these possible issues, then you may be looking at a far more difficult repair project. Even so, there are a few other things to check before you delve deeper.
Start with the car’s fan. If it isn’t working, a fuse may have blown, a wire may be frayed or a sensor might be bad.
Inspect the compressor clutch to ensure it is engaging. If it isn’t, check the fuse. If the fuse is OK, remove the compressor clutch relay and check for power and ground on the relay control coil terminals in the socket.
It’s at this point that air conditioner repair can test your skills or even be beyond you, especially anything involving the compressor, condenser, accumulator, evaporator and the orifice tube or expansion valve. Some say to leave this job to the experts. The cost of the tools required and understanding precise measurements alone may have you turning to a mechanic.
Check out all the air conditioning system parts
Photo courtesy of Matthew C. Keegan.
Matt Keegan has maintained his love for cars ever since his father taught him kicking tires can be one way to uncover a problem with a vehicle’s suspension system. He since moved on to learn a few things about coefficient of drag, G-forces, toe-heel shifting, and how to work the crazy infotainment system in some random weekly driver. Matt is a member of the Washington Automotive Press Association and is a contributor to various print and online media sources.