Turn acc off before turning the engine off?

[solanog]

A friend of mine said his mechanic or air conditioner technician, said to him, as an advise, to turn the A/C off before turning the engine off. Supposedly this will extend the A/C life.
Is this true? If it is, Why?
I never turn it off neither before starting the car nor when turning it off. Am I killing my car or A/C?

[ebpda9]

i have no idea why he said that to you, but i've heard it before. i didn't look into it, because i never use the ac, unless my windows get fog on them

[blind34_1]

yeah, I guess its easier on the ac pump also a little easier on your engine I guess too. I cant give you an answer why, I just seem to know this. just whenever you turn onto your street to go home or whatever, pop off your ac. theres no reason to keep it going for thats short of a time, and you might as well save on wear and tear.

btw: ac is for wussies. 360 ac is the best (unroll both windows, sunroof and go 60mph.)

[94_AcCoRd_EX]

Ya, there was another thread on this fairly recently. I always turn mine off before I start the car.

since i have a remote start system, i usually leave it on the right settings so my car gets tosty or cool before i get in. did that for like 1 years now, still works great.

[ifeldwn02]

i've always heard that and to turn ur radio off before u turn the car off

[Accord Man]

turn off everything..

I'd think of it as being a bigger deal to turn it off before turning the car ON. It's pretty bad for a compressor to go from 0 RPM to 2000 RPM in a few milliseconds. When the compressor clutch kicks in it takes longer than that to engage and is a little smoother on the compressor.

Equally it could possibly be bad for the compressor to go from idle to 0 in such a short time as well.

b

[BlackWolf]

The reason why you turn off the a/c before you start the car is because it puts a strain on the battery, it's an extra draw on the battery power when starting the car and why you should turn it off before you turn off the car is because more than likely you'll forget to turn it off before you start the car again and also because it gives the alternator a chance to charge up the battery before you turn the car off. What all this boils down to is trying to extend the battery life. I always turn my a/c off just before I get to where I'm going, it's still going to blow cold air for those last few minutes anyways and always leave it off before I start my car, then turn it on after the car is started. I went through a few batterys before I finally asked the a/c tech "what's going on?". He also stated that you need to have the air recycle button pushed on your dash when you've got the a/c going and to have the fresh air button pushed when you've got the heater on. The idea for the a/c recycle air button on is that you are going to be cooling already cool air so your a/c pump doesn't have to work soo hard. Plus it's better on your gas milage too. Hope this helps.

[ebpda9]

yeah that makes sense

i like to roll all my windows down and turn the heater up to max at night.. feels great.....err, 3 in the mornin; and im trippin. HAHA!

[TonitrusEN]

thats what i do Raku

Turning the AC off before turning off your car shouldn't help the battery charge any more than if you left it on. The AC is through a mechanical linkage via a belt and thus puts a mechanical strain on the engine and should have no bearing on the electrical system. The alternator runs off the same mechanical linkage, but the engine doesn't run slower with the AC on. In fact often times in my car the engine idles faster with the AC on rather than off, so the alternator would charge the battery more at idle than with the AC off. Unless the AC has some kind of extra electrical system that I'm not aware of then turning the AC off a few minutes before shutting off the car won't help your battery.

Running the AC while recycling is definitely a more efficient way to go. Running the heater with recycle on is also a more efficient way to go if you want to heat your car faster or run the heater less, but since running the heater also assists the engine cooling system then it's probably more efficient for the engine to leave the outside air coming in.

Having the AC off before turning on your car is definitely helpful for the battery, however it's also helpful for your compressor.

b

[Accord Man]

about running the heater on recyling, its often not an option since the accumulation of humidity on contact with the cold windows forms condensation..

----------------------------------------------------------------------------------

During the cranking process, voltage isnt constant.. So thats why we should turn every electrical item off.. And anything that could potentially extend the firing up should be turned off as well (for obvious reasons) --- read AC compressor.

i remeber my pops had an old big ass boat of an oldsmobile and he HAD to turn ther a/c off when turning off the car or else it would not come on again (fan would just blow hot air) good ol times bein a kid. dont know why, didnt care at the time. And NO, a/c aint for no wussies, you are all mid- easters, candians, or norcals and dont underrstand how hot it can get in so cali. Hell, you come down here and you go ahead and drive with your windows open, just know i'll be chillin when it this triple digits.

When it's > 98F outside and you try to pull the ole 2-60 method, you're simply driving in a convection oven. AC gets a from me.

b

glad soemone agrees!!