Here's how I disabled A/C on Defrost modes on my 2015 LX Fit (Canadski-LX).

Warning - this is a permanent changed-functionality - graphic images of cut wires follow -


1. Take the glove box out by pinching the sides in to tilt it out of the dashboard and then pull the hinged bottom to remove it - follow the blue wire to find the climate control unit.








2. Here is the back of the climate control unit, white plastic structure on passenger side.








3. Behind the mode select knob there is an ordinary microswitch to turn on the A/C, you can hear it click when you when a defrost mode is selected.








4. Good luck pulling out the plug, I gave up and just cut the yellow wire.








5. Close up of the cut yellow wire.







Success !
Now I can run the defrost modes without A/C, and the A/C pushbutton still works to turn it on manually.

Note that this is permanent unless you are able to reconnect the cut ends (and have way more patience than I do).

Cheers!

 

One note I would add to this is that if you're going to cut something like that, try your hardest to leave enough wire there to do a splice to reconnect it. The one in the picture is pretty much a lost cause because even if you had it out of the dash it would be pretty difficult to put a splice on that wire. Some may not care because they don't want the feature, but I would always want to leave a way to return it back to the way it was.

Nice find by the way.

 

Yes I totally agree.
In my case I was certain that it would never be reconnected, but many folks will want a reversible solution.
Maybe someone with a dental mirror (and more patience than me) can find out how to unplug the switch without breaking anything.
Thanks should go to the 2nd gen folks who inspired this by showing me how to do it to my Fit Sport (RIP).

 

OK, I'm curious. Why would you want to do this? If it's not needed, why is that the way cars are made? I've never thought about it before now. Every car I've had uses the a/c for defrost. I just figured it had to?

 

Because they know more than Honda???

 

good find! i will pull this plug when i open the dash back up for a more permanent sirius solution. thanks!

 

One reason is that it robs power from the little 1.5L engine, which negatively affects fuel efficiency. I'd love to be able to deactivate this automatic defrost mode but am not brave enough to cut wires and make it permanent. When I owned a Lexus awhile back, there was a user programmable Personal Setting you could change to deactivate this. That was very convenient, although I wouldn't expect a subcompact to offer that.

 

Because they know that some customers are going to drive around with their recirc switches on and condensation running down the inside of their fogged windows!

 

So I have a question ... the AC condenser kicks in at defrost as long as the heat selector is in the blue? And as long as the selector is in the red, you get heat? It's either only AC or only heat coming out of the defroster, right? No way to set for outside "untreated" air (not from heater or AC) only unless you perform this wire cut?

 

No, that's not quite how it works. if you have it in defrost mode, the A/C compressor will be on regardless of where the temperature setting is (i.e. hot or cold). If the temp selector is set for hot/warm, you will get hot/warm "conditioned" air. "Conditioned" only means that moisture is removed from the air.

 

The whole idea of defogging the windows is to remove the moisture by having dried air blow on the window hot or cold. Obviously this can be accomplished with the open air vent and not recirculate. Disabling the ac compressor prevents the moisture from being removed. If its raining outside you are essentially blowing damp air on the windows not really doing anything. It may make the fogging worse.

 

I have a question as well because I'm a little confused. Is the A/C light supposed to go on as well? I assume so but this doesn't happen in my car. If I put it on defrost with the selector turned to the warmest setting, the A/C doesn't turn on at all. I have a Canadian EX model for reference.

 

The AC compressor Will turn on but the light will not illuminate…

As for why you would want to do this, when I lived in Portland Oregon I found I didn't need to run the AC compressor defog the windows. Not sure exactly how the weather/climate they're allowed that, as it's almost a requirement in Texas to have the AC running all the time

My 2001 Honda Civic allowed the user to select if the AC turned on or not during defrost... It was a sequence of holding some buttons but nice to not have to use the AC to accomplish the task.

 

It is my understanding that the AC only comes on when the mode control dial is set to "defrost" (far right setting), but when set to "floor and defrost" (second from right setting) the AC is not employed. I find floor and defrost mode in combination with fresh air to be sufficient for defogging and defrosting in all but the most extreme cases.

 

This is not correct, my AC compressor on my EX kicks on with floor and defrost selected. The icons show these two settings must be used with fresh air and not recirculate.


If one were able to allow the choice of AC or not with the wire cut, maybe add in a switch somewhere, then I'd call it a worthy mod. Snipping wires to me doesn't constitute being a good mod unless you can use the equipment they way it was originally intended for. Having a "mod" means to me having something more than what OEM has, but still retaining OEM functions. What the OP has done is "changed" the functionality, not "mod'ed" for extra functionality. Sorry, pet peeve of mine.

 

[QUOTE=Bassguitarist1985;1302413]This is not correct, my AC compressor on my EX kicks on with floor and defrost selected.










Thanks, I stand corrected, the AC does cycle on in both modes my LX as well. Just tested it in the garage with the door shut for quiet, and could hear the subtle click of the compressor from inside the car-no significant change in idle sound from the added load though... My misunderstanding was partly from the way previous cars worked, and the IMO not so clear manual info on this point.

 

We've got it covered ...

 

Sorry, but just to clarify, the compressor turns on but the light stays OFF?

 

Yes the light only indicates that the a/c pushbutton switch is pressed.

 

I learned something here so thanks bzdang. The existing AC switch allows one to add AC at will, so your simple disconnect gives the option to add AC for defrost/defog use only when desired. Very clever simple alteration. I probably won't do it myself as I'm happy with my fit's mileage and power, but I get the idea, and know more about my car now.