As we get more and more into the cool season here in the U.S., in most parts of the country your car's A/C is not needed much any more for keeping the inside cool......we're starting to use the heaters more and more. However, it is necessary, even if we don't use the A/C for cooling, to periodically run the compressor for at least a couple of minutes a week or so. This will keep the compressor's moving parts lubed, the compressor clutch working properly, the lubricating oil circulating, the seals in the system intact, and help prevent freon and refrigerant leaks ( most of the systems after 1994 are R12-type freon systems ).

When it's cold outside, you don't have to put up with an ArcticCool blast from the dash vents. Most of the manually-operated climate control systems today allow you to turn the A/C button on and add heat from the red / blue scale temperature **** or lever. Just press the A/C button, make sure the small built-in light signifies that it is on, set the fan speed where you want it, adjust the vents, and either rotate the temperature **** or slide the lever toward the red end of the scale to add heat as desired....obviously the engine should be warmed up first. If it is humid outside, make sure the fresh air mode is selected instead of the recirculate, which could fog up the windows. After about 5 minutes or so, turn the compressor back off and re-adjust the heat setting....it will be warmer because the flow of cold air from the compressor mixing with it is gone.

On many vehicles, and on most of those with automatic climate systems, the A/C compressor goes on automatically with either the windshield defrost or the split defrost / floor vent setting....so this will automatically be done with the defrosting. You may or may not have to add heat manually depending on the unit's design. Blowing cold air directly onto the windshield from the A/C compressor without heat, though, is not a good idea...the window chills down and moisture outside condenses (or freezes) onto the outside of the glass. That is why you should add heat, if possible, to the defrost.

Some vehicles, when it is below about 38-40 degrees outside, do not allow the A/C units to run.....even in defrost......to prevent internal system freeze-ups. Obviously there is nothing you can do then, but as soon as it gets warm enough outside, run the A/C compressor ( with heat ) as described above....and you can run it in a heated garage.

Doing this at least once a week or so, like regular oil changes, is good insurance for your car. A/C repairs can be difficult and expensive ( requiring special EPA and CARB-approved equipment ) and refrigerant leaks can be hard to find, sometimes requiring special dyes to color the escaping freon so it can be detected.

 

Thanks for the A/C advice. I live in California and it doesn't get too cold. I just leave the A/C off since it's not hot anymore and also to conserve gas. I can go weeks without the A/C on but now I will periodically run the A/C to keep the lubricating oils circulating.

 

This advice is usually given in the Owners' Manual.....I just post it here in the late fall because people sometimes forget.

 

Good advice. Living in Hawaii we pretty much use the AC 24/7 even during the winter months. Surprisingly I as well as most of my family have never really had AC failure even with 10+ year old cars.