Using air cond

I have heard that the air cond. in a car should be turned on once in awhile in the winter time to lube the pump. Would some of you better mechanics voice your opinion on this, also how often & how long should it be run. Thanks

Yes, this is a good idea. You’re not lubing the “pump” so much as you are the o-rings and seals, which keeps them from drying out and creating refrigerant leaks.

I’ve heard varying numbers on how long to run it, but I believe the middle ground is about 15-20 minutes per month. Basically, run it once a month for a decent length drive; that should take care of it.

Using the A/C in winter does keep the refrigerant oil in the system circulating which in turn keeps various seals, etc. from drying out.
With most A/C systems the air compressor will operate in the DEFROST mode so if you use that setting you’re accomplishing the task.

Other than that, it’s pretty much a non-issue in my opinion. Run the A/C for few minutes every couple of weeks for peace of mind I suppose.

In order to be effective, in some areas, you will need to do this on a very warm day or the compressor will not run or will not run for long enough to do anything.

What year. make, and model?

In most new cars the AC is engaged to remove moisture every time you turn on the windshield defroster.

And in others (most newer cars) you will get the A/C on anytime you hit the defog.

It takes a lot more than tuning the switch in the right position to get the compressor to run enough to move lube around. If the temp is too low will it do anything. I can’t test mine here since it is never winter in New Orleans. I expect to be in NY as usual in December, maybe I will open the hood on a couple of cars if it gets below 20 F and see how long the compressor clutch cuts in.

Yup, it will operate even of the temp is low. Passing the cabin air by the cooler coils in the evaporator is the only way to remove the moisture.

I can tell the difference in my car. Like most “automatic” features of today’s systems, it has a weakness. In the winter when there’s ice on the windshield, I’d prefer to blow the air at full heat through the defrost vents to melt the boundry between the ice and the glass, making removal easier. When I hit the defrost button, which is the only way to direct the air through those vents, the air doesn’t come out as hot as when I just have it set to the dash/floor vents. Some of the heat gets removed by the evaporator before the air gets passed through the heater core.

I can’t test mine here since it is never winter in New Orleans. I expect to be in NY as usual in December, maybe I will open the hood on a couple of cars if it gets below 20 F and see how long the compressor clutch cuts in

It will.

Yep, no need. When you turn defrost on, it turns the air on to clear the humidity. Generally though it has to be above 32 degrees or so before it operates at all. So bottom line don’t worry about it.

Well, it actually still runs below 32 degrees but the air is so dry at that temp it doesn’t have much value.