My wife tends to leave the a/c in the on position when she shuts-off her engine. So when she starts it up, it automatically comes on. I believe that by doing this, she is putting too much of a load on the battery and starting system. Her last vehicle, a 97 olds, went through 4 batteries in 3 years because of this I believe because nothing else was ever found to be wrong with the charging system. Am I correct or are the newer vehicles protected enough to prevent this. She has a 2004 CRV. Thanks

 

I had a girlfriend who insisted on turning off the HVAC and radio every time she turned off the car... kinda interested in hearing people's opinions!

I think that when the starter is active everything else shuts off, but I'm not sure.

 

The A/C will not come on until the engine reaches a set RPM,and the starter couldn't possibly turn it that fast.

 

That is the problem I think.

 

Im also obsessive about turning off the air conditioner/heat, radio, etc any time i turn off a vehicle. Its just how i was taught! I was told there is less wear on the battery at startup and it prolongs your battery life. My grandfather pretty much taught me everything i know about cars so i dont know much about the modern engine....Someone with more knowledge please clarify!!!!

 

relays switches and thingamabobs...

basically a lot of the extra load is switched OFF when the starter is engaged, specifically anything tied to the ACC circuit

 

I've been told the same about the A/C from my grandpa...Can't say I use it often though, I prefer the window

 

It wont have an efffect. When you turn the key to start it turns off the acc power functions, until the start sequence is off. So it will have no effect.

 

So there is no effect on the battery whether or not you turn your A/C on or off before shutting off your car?

I get fussed out by my gf all the time for leaving the A/C or heat on when I shut off my 4runner. She seemed persistent enough that I just started doing it because I got tired of hearing her. Would be nice to have a good intelligent comeback for her one of these days

 

Ever wonder if she was using crappy batteries and leaving lights and junk on alot?

Heck, a/c doesnt exist to me-I only run it if its to unbearable to touch anything in the car..which isnt often.

 

Okay.

No, leaving ANYTHING on when you turn off the car isn't bad for the starter in the least, nor bad for the electrical system. You can cause drain by adding aftermarket stuff, but that is only while the car is running.

As was said, when you turn the key to "start", everything else shuts off.

 

Correct. Only thing that will stay on when cranking are things that will still work with the keys out of the ignition, like the headlights, hazards, horn, etc.

 

My step-dad always yelled at my for leaving my stereo, A/C on when I shut my cars off. I have never replaced a battery in any of my cars. I had my 4Runner for 3 years, my Celica for 1 and my Jeep for 1 now. My GF also shuts everything off, because she was told the same thing. To each their own I guess.

 

So, it's starting to sound like if you shut everything off you're a girl.

 

My step-dad shuts everything off...

 

or if your tired of having one make a big deal out of it whenever you leave it on

 

Maybe on OLD cars the acc didnt shut of when you went to start, but on everything I have driven built in the last 20+ years it shuts all the acc off when you go to start... not an issue at all. And I also cant see it killing batteries, maybe causeing a slightly slower start, but not killing batteries.

 

Ok, thanks for all of the replies. I had always turned everything off except for the stereo. I guess she is off the hook. Now I have to find out why she needs a/c when its 55 degrees outside. LOL

 

Good luck with that!

 

Mythbusters.