Air conditioning compressor shortcycling?

[Benji]

Hi! I bought the car used at about 9000 km and since the purchase I have wondered the AC. It seems that when AC is on, the compressor starts and stops all the time, making quite unhealthy type of sound. The AC does work well though.

Typically short cycling on AC compressors is considered to be a bad thing, but of course car compressors might work differently. Does this sound like normal behvaiour to you?

Thanks!

Video below:

[londiniumperson]

Mine shorts cycle occasionally; you say that the your car's compressor starts and stops all the time, can you clarify? Do you mean as soon as you turn the car on before you start driving, whilst driving and after a drive, every single time?

[Benji]

Mine shorts cycle occasionally; you say that the your car's compressor starts and stops all the time, can you clarify? Do you mean as soon as you turn the car on before you start driving, whilst driving and after a drive, every single time?

It does that all the time. When I start to drive the car, while I drive the car until I turn the power off. Only way to make it stop is to of course turn AC off completely. Sometimes it sounds to spin faster though, but it always shortcycles.

[EEEE]

Mine is the same - quite annoying that the fan control is not more integrated (eg variable speed fan control).

[Verone]

A lot of EVs function like this with a short cycle to maintain temperature more accurately, because their compressors are direct driven.

In 99.9% of cases with an ICE car, the AC compressor is clutched in on an accessory (serpentine) belt, and the cycles are longer to prevent premature wear on the clutch that's in their pulley, and to minimize additional wear on the other associated pullies and idlers (alternator, PAS pump, and sometimes the water pump if it's not run off the timing belt) on the same belt as the load increases and decreases on the belt.

In an EV, there's no accessory belt to worry about, so no clutch, it's literally just switching a motor on and off. I have a mate with an electric Kona, and he thought there was something wrong with it because it was behaving exactly the same way and he could hear it when it was in his garage.

It's weird when you're used to an ICE car, but it's perfectly normal.