A/C on with Defrost

Huh , interesting , mine never leaves those 2 haha , but I think I've only used AC once in 5 years

 

Difference in climates, I guess. I use the floor vent for heat in the winter, and the dash vent for fresh air in the summer, and occasionally a/c on really hot days.

 

I have owned many Honda's & still own one, I think it works the same as the Toyota, (Not sure) I will check the next time I drive it. Maybe this mod is good depending on where you live, I can see in a dry climate where turning it off might be a good idea, but I just don't see any big advantage, but again to each their own, When I do something I don't ask permission & neither should anyone else. I do get nervous when messing with the wiring on a vehicle, Toyota has some pretty good engineers & sometimes things that don't make sense to me makes a lot of sense to them. As to cars without air working good, well I am an older guy & remember having a lot of vehicles without air, & no, they didn't work just fine, they worked, not good, but they did work. jmop

 

My wife's Honda can be turned on/off while in defrost. She prefers to keep in on defrost 100% of the time because it doesn't bother her dry eyes that way. If she couldn't turn off the a/c it would be running 100% of the time.

I forgot it did take a sequence to make it work that way. At least Honda allowed owners a way to do it, without cutting any wires.

From Honda owners manual:

To deactivate automatic a/c feature:

1. Turn vehicle off.
2. Turn fan knob off.
3. Turn temperature knob all the way to the left (blue area..
4. Turn vent knob to panel only setting (next to max. a/c..
5. Hold down both air re-circulation button and a/c button while turning the key to the "run" position (one short of starting..
6. Continue holding for 7 seconds until air re-circulation button stops flashing.
7. Anytime you engage defrost or defrost/heat positions, the A/C will automatically turn on. Press the A/C button to turn the A/C compressor OFF, the light will go out.

Since the wife leaves it on defrost all the time, it stays a/c off and she can turn it one if needed. If she switched to any other setting and then switches back to defrost the a/c light comes on and she can just hit the a/c button to cancel a/c.

I guess defrost effectiveness is different depending on climate. Humid foggy climate may work well with a/c on, but living in WI, IA, CO, I've never had issue with poor defrosting. I'm an older guy too and can't recall ever thinking the non-a/c equipped vehicle wasn't defrosting well. Heavy rain and the right temperature and the a/c goes on.

 

Well said, I will try that on my Honda. Well, not to argue, but growing up in Wisconsin/Minnesota I had many a cold damp morning & I would hit the defroster & the inside windows of the car would instantly be covered with dew/mist (can't come up with a word) that had to be wiped off, & took forever to clear. there were many times when I had to pull over & wipe the windows. jmop

 

Thanks for the write up. Worked great on my '12!

 

I've probably needed a/c on driving between Albert Lea and La Crosse, for whatever reason it seems like every time I drive back to La Crosse as soon as I reach Austin/Albert Lea the weather goes to shit either torrential rains or blizzard conditions?

 

AND that's the point of this mod. It gives you the choice IF YOU NEED IT.

 

Agree, everyone should do as they want, I was just stating an opinion, on some of these mods I am not sure If I want to take the advise of someone on the internet, (NOT saying they do not know what they are doing) but this is the INTERNET, electrical issues being of most important, new vehicles are reliant on electronic analysis, &sometime the cutting of wires can upset this process, & I would worry about possible compressor issues, the benefit of this mod is so small I would not consider it, HOWEVER!!!! should anyone want to I say GO FOR IT, This is just my opinion, everyone should do as they want!!! jmop

 

So I need a little clarity. If the AC light is NOT on, is the compressor still engaged with defrost? OR is the light the realtime on/off indicator? Because my light only comes on when the heat dial is all the way to cool, unless I push the button!

 

The A/C indicator will not illuminate when the selector is set to defrost windshield (on my 2011 anyway). However, if you let the truck idle you can feel the A/C engage and disengage as it cycles.

 

As I suspected. I do feel that slight shudder when I put it onto defrost, just wasn't sure, thanks... Might consider the mod!

 

This. I've never seen anything stating a temp at which it would not engage for my 2006. If it's below freezing, I want all the heat I can get before I leave for work. There's a noticeable difference in the temperature of the air coming out the vents in defrost mode vs feet only so I know the AC is running.

I've also noticed the slight engine lag while driving up a hill with the defrost or normal AC mode on. So it would be beneficial to turn it off. I just use feet only mode 99% of the time to get around that.

My nissan is more annoying. If you turn to either windshield mode it turns on the AC like this, but changing modes doesn't turn it back off. We have to turn the fan off then back on to turn the AC off.

 

To vssman: How did you disable the A/C on when temp dial is in cold position? I see one mechanical solution on the forum (restricting how far the knob can be turned) but am wondering if there is an electrical solution to this. I want to do both mods, as I find both the defrost A/C and the auto-on feature very annoying. '11 SR5

 

There's a thread. http://www.tacomaworld.com/forum/2nd-gen-tacomas/307481-auto-max-ac-mod.html It's an electrical mod similar to the one on this thread. Careful about posting if you do it 'cause some folks will get their panties in a bunch about you modifying your own truck...

 

Thanks! Did both mods this evening, in about 10 minutes each, not counting the time to buy a small butane powered soldering iron at Radio Shack (works great). Wish I had done these mods years ago. No more unwanted A/C air.
BTW: I used the wire splicing technique described here: http://www.backinblackgp.com/Tap_And_Splice.htm

 

I noticed this as well. I did the mod exactly as described a few weeks ago on my 2010 but today I popped the hood and watched the AC compressor cycle on defrost regardless of whether or not the AC button was activated. It seems like all the mod accomplishes is that it allows you to turn the light on the button on and off but the AC remains on all the time with defrost

 

I can tell you it works on a '13. I purposely watched the ac compressor stop spinning when the button was pressed to turn off the light while in defrost. Pressing the button again to turn the light on turned the compressor back on. I also made sure the compressor stayed off when the light was off with it in defrost just to make sure it wasn't a case of the compressor cycling on/off. Could you either have wired something wrong or does the '10 have a different harnes (I don't recall exactly what years use what diagram)?

 

And the 2009+ fix (post 157) works on a 2014 DC also. Funny, wife's VW Beetle requires a manual push of AC button with defrost, but as early as my old '89 Ranger, the AC came on with defrost, without AC light notification. AC defrost is often needed in the damp PacNW, but not always. Easy enough to push the button, if needed. Thanks!

 

disconnect green and splice into pink is what I did, looks just like the instructions on page 8