With spring now in full force, it’s time to make sure your vehicle’s air conditioning system is ready to keep things cool as the heat of summer driving approaches. There are several items that every vehicle owner can check out on their own, while other jobs should probably be left to a trained professional technician.
The first and easiest task is to just check the function of the system by turning it on. Unless you drive a hybrid with an electrically-driven air conditioning system, the air conditioning (A/C) compressor is almost always driven by a belt turned by the engine. That means you need to start the engine for the air conditioner to provide any chilled air.
With the engine running, turn on the air conditioning and verify that cold air is coming from the vents. Cycle the fan control to ensure that the amount of chilled air can be varied. If you can feel cool air but it isn’t blowing, you may have a faulty ventilation fan or it may simply be a blown fuse. Check the owner’s manual to find out which fuse controls the fan and replace it if necessary. If the fuse is good but the fan still doesn’t work, it’s probably best to bring the vehicle into your dealership and have a technician check it out.
If the fan is pushing out air that is not quickly cold, shut off the engine and take a look under the hood to inspect the accessory drive-belts on the engine. For safety reasons, it’s really important not stick your fingers or any other object near the belts with the engine running. On a rear-wheel drive car or truck, the accessory belt, along with the A/C compressor, will be found at the front of the engine. On most front-wheel drive vehicles in which the engine is mounted sideways, the “front” of the engine is usually found on the passenger side of the engine compartment.
Inspect the belt or belts with the engine off to ensure they aren’t loose, frayed or broken. Most newer vehicles will have a single belt that wraps around several pulleys, including the alternator, air conditioning compressor and possibly a hydraulic power steering pump, while older vehicles may have two to three belts. If you push on the belt mid-way between two of the pulleys, there should be less than half an inch of slack on the belt. A frayed belt shouldn’t cause A/C failure, but it should be replaced, so it doesn’t break while you are driving.
As the engine packaging on newer vehicles gets increasingly tight, belt replacement has become more difficult. If a belt needs replacing, you should take your vehicle to your dealer and have a trained technician take care of it.
If the belt(s) is in good shape, the most likely sources of air conditioning problems are the compressor or low levels of refrigerant. Over time, refrigerant can slowly leak out of the air conditioning system and require a recharge. Vehicles built before the mid-1990s all originally used a form of refrigerant known as R-12. Because R-12 caused damage to the Earth’s ozone layer, it was banned from use and replaced with R-134.
Older vehicles originally built for R-12 can be upgraded to run with R-134, and over the years many have already been modified. This is not a do-it-yourself sort of project and if you still have an older vehicle that uses R-12, the upgrade should be handled by a pro.
Drivers shouldn’t try to recharge their vehicles on their own and can get this service done by their dealership. A factory-trained technician should inspect your A/C system for leaks and other problems before your system is recharged, anyway, to avoid wasting refrigerant and money.
If the problem is with the air conditioning compressor or a leak somewhere in the system, the repairs should definitely be handled by a professional. Taking apart the system and putting it back together without damaging seals is a not a trivial task, and if you don’t get it right it can be far more expensive to fix than if a technician did it in the first place.
Now is the time to check out your air conditioning and have it serviced before you get stuck in a traffic jam on a 90-degree day. It costs nothing to do the basic checks, and getting service now will prevent grief later.
This article is presented by Jack Maxton Chevrolet in Worthington, Ohio.