A/C on with Defrost

I'd imagine the the engineers thought behind it is, that your average person who drives a vehicle use's the defrost atleast once a week.


I am sure that most of the younger guys/gals on here dont remember having more than one belt driving the accesories under the hood. If you do, back then when your alt, P-Steering or AC all had seperate belts, but if the AC belt broke, if you left it off for more than a couple of weeks or so, you'd be replacing the AC


Remember, all the auto makers use this technology. I am sure that if it werent necessary that would not use it.

GM stopped putting DRAIN PLUGS in their tranny pans some 15-20 years ago that saved the Company $15 Million dollars ( I think was the number )

 

After our recent rains here I do miss the control panel in my 99. Complete control by the user. Has there been a decision made for which wire should be cut/dismantled for the 09s?

 

does a/c on really affect gas mileage

 

Its kind of like your home. When you turn something on, it costs you money.

 

Sometimes I put it on defrost, then forget to take it off for a couple days... I do notice a drop in mileage... not a whole lot, but every penny counts.

 

I'm also still curious as to whether anyone has had any success with this on the '09? I've been unsuccessful in removing the wire, and one person mentioned that it is no longer the solid green wire. I also noticed that my connector is white, while the one in the picture is black... so it makes me wonder if they've made changes to prevent this "feature" from being disabled.

 

You could just put the selector on "feet only" and avoid the AC completely. It still blows air from the windshield and side window vents along with the floor ones. That's what I use all the time. Defrosts/defogs the windshield and front windows without the AC making it take longer to warm up or having to figure out what wire to remove.

 

its really that easy...freakin awesome! thanks again..i have mentioned it many times and will do again...I LOVE THIS PLACE!

 

Well, getting that darn wire out of the plug just about killed me I gave up after an hour and just cut the wire! Much easier.

 

did you notice a problem before this mod, where the engine would surge (raise rpms) when stopped or slowing?

I have a theory that this surge is caused by the a/c compressor kicking in when the HVAC controls are set to defrost.

I believe my surging is all gone now that I've done this mod

 

Anyone figure this out for the 2009s yet??

 

Nice! Check for this MOD.

 

I was going to do this mod, but I don't think this mod is necessary on the 2009's. When I run my defroster the A/C does not come on. I can turn the AC on if I want to, but it does not have to be on. I appear to have complete control.

Perhaps Toyota changed this on the 2009's?

 

I'll check my '09, but I think mine comes on.

The AC/defrost combo was developed in the 1970s by GM (IIRC) in an effort to meet Federal Motor Vehicle Standards for defrosting windows.

A lot of older cars need a half-hour warm up to clear a dollar-bill size area in an iced up windshield. Or go completely foggy when you hit a summer rainstorm.

Also, the running of the AC on a regular basis keeps compressor seals in the game.

Once the windows are clear, I usually adjust back to vent or floor. No wire snipping needed. YMMV.

 

Checked my '09--AC on with defrost. Heats up quick, clears them winders good too.

 

Fascinating. I checked mine again and the AC does not come on. I can turn it on but it doesn't come on be default.

When defrosting, I can't change the recirculate mode, it will always draw in air from the outside--that I can't change.

 

Are you sure it doesn't come on? On the ones it DOES come on, the AC light on the button is still off. But the compressor still cycles.

 

Perhaps I need to be more scientific about it, because I was looking at the LED for the A/C status which does not illuminate when defrosting.

 

Yeah, my 98 Corolla does a dim light on the AC to let me know it's in defrost mode, but the truck doesn't. If this is something Toyota has been doing at least from 98 through 08, then I can't imagine they stopped in on 09. Although it would be nice if they left that option up to the driver. When it's below zero out I don't really want the AC on making things even colder while I try to thaw the windshield.

 

From on-line 2009 Tacoma manual p226​

It seems that a/c is NOT on in defrost mode, unless turned on by operator - see below
NOTE: Type "B" is truck with a/c type "A" is truck w/o a/c.​

"1. Using the air conditioning system and defogger​

n

For quick clearing of the windshield and side windows (type B only)

Press to turn the air conditioning on.
n ​

​

Using the system in recirculated air mode

The windows will fog up more easily if the recirculated air mode is used for
an extended period.
n ​

​

When outside air temperature approaches 32°F (0°C) (type B only)

The air conditioning system may not operate even when is pressed.
n ​

​

When is selected for the air outlets used

For your driving comfort, air flowing to the feet may be warmer than air flowing​

to the upper body "

Guess need to check underhood with defrost on to confirm in 2009+ Taco's.

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