I have a 2007 Mazda 3 Hatchback. For some reason, when I turn on only the fan of the climate control system - to let fresh air in, it sounds like the compressor turns on. It's obvious something activates, and I'm pretty sure it's the compressor. The air doesn't get cooler or de-humidified, or anything like that. But when i turn the fan on, the compressor activates, and I feel a small kick in the car too when the compressor turns on. Is this normal?

 

Read your owner's manual. The AC kicks on automatically when certain modes are selected (ie. where the air is going). If you want to avoid having the compressor turn on, you need to be careful which mode you choose. You didn't say which climate control system you have, so I can't offer more specific advice.

 

Simple. You probably have your temp setting to "all the way" cold. Turn it back 1 notch. This will prevent the a/c from coming on.

 

I have an automatic climate system, but I using Manual Control. For example, I turn on only the fan and set it to 65 degrees manual, not automatic. And the outside/ambient temperature is 55 degrees. With those settings, and any other settings, the compressor turns on. And the a/c button in never illuminated. I still have the option to illuminate the a/c button to make sure the compressor is on too. So for some reason, the compressor turns on when I have my system set to fan only, manually, and a/c button not illuminated..


what's going on?

 

Have you looked at your manual? It explains its very clearly in Section 6 (in my manual, it is page 6-10).

The AC is AUTOMATICALLYON if you direct the air: 1) Completely at your feet, 2) Completely toward defrost, and 3) Split between feet and defrost.

 

Thanks... you're right.. and I contacted my service advisor also. I dont understand why the a/c must be on when venting to the floor only. It's a waste of gas if you ask me.

Thanks for letting me know

 

When the defroster is running, it's a good idea, because most ppl don't know how much that can help in the defrosting process. I've had many ppl thank me in the past for that information, like I was a God or something... in the old days before it was std for the A/C-defroster thing became so std.
But I have to agree w/you about the floor area. STUPID and wasteful. I usually keep mine just to the left of the compressor kicking in... in that inbetween settings area. That has solved the problem for me.