A/C compressor kicks in when heat is turned on, why?

[rdanville]

I pull the fuse on mine during the cold months. I don't run my home AC periodically so why should I run the car AC periodically? Never had a problem. Usually about April 1st I put the fuse back in.

[JW657]

Personally, I don't care at all. I let it do what it wants, if it doesn't work correctly, than I fix it. It doesn't bother me, it has no impact on how I drive, it isn't really noticeable. The gas savings from not running it would be negligible. Besides, cars get far worse fuel economy during colder months anyway. If you were trying to race someone, then it might matter.

[Tom S]

I find the AC compressor needlessly kicking in an out to be annoying. I also am not convinced or the merits of it drying the air unless that becomes an issue in warm damp climates like down south.

[JW657]

Originally Posted by Tom S

I find the AC compressor needlessly kicking in an out to be annoying. I also am not convinced or the merits of it drying the air unless that becomes an issue in warm damp climates like down south.

Personally, I find it helpful. I live in a cold area and when the car finally gets warm, the moisture in the air wants to condense on the windows, because they are cold. If the A/C is working, the moisture will condense on the evaporator core as it passes through the HVAC system in the dash, it's a pretty simple solution. My A/C works great otherwise, I think KhanTyranitar has a great point, if you don't run it for months at a time then you might find that it doesn't work so well when you actually need it.

[the_intimidator_02]

Originally Posted by Bob R

I read somewhere on this forum that the A/C doesn't run below a certain outside temp when in defrost. As far as having to have dry air to defog a window....that's a bunch of BS. I've been driving since 1965 when there was no AC hooked to the defrost position on cars then and the window stayed just a clear and cleared just as quick as today with "dry air".

I've also driven cars with no A/C and there is a difference. It really comes in handy when it's raining and humid and the windows are rolled up. In winter I find it helps, and A/C will run below freezing. It's been -15 Celcius here and my A/C kicks on and off.

[SoNic67]

Originally Posted by rdanville

I pull the fuse on mine during the cold months. I don't run my home AC periodically so why should I run the car AC periodically? Never had a problem. Usually about April 1st I put the fuse back in.

Originally Posted by Tom S

I find the AC compressor needlessly kicking in an out to be annoying. I also am not convinced or the merits of it drying the air unless that becomes an issue in warm damp climates like down south.

Better one - read the owner manual. You will find that putting the knob on "VENT" or "LOW" positions provides just heating, without the A/C function. No need to dis-assembly the car.

Originally Posted by Bob R

As far as having to have dry air to defog a window....that's a bunch of BS. I've been driving since 1965 when there was no AC hooked to the defrost position on cars then and the window stayed just a clear and cleared just as quick as today with "dry air".

That's because you live... where you live. If you would have 80-100% humidity in the mornings, with temperatures below dew point, you would think differently.
All the modern cars do this de-humidification - Hyundai, Toyota... you name it.