A/C on with Defrost

Interesting.... So maybe they finally solved the problem of freezing even faster by having the AC on during the winter in defrost mode?

 

Checked my 09 (built Sep 08). When in defrost mode a/c is ON dispite what the manual says. Confirmed by feeling underhood a/c plumbing while in defrost mode and the a/c lines were cold. With defrost not selected, the a/c lines lost their cold and warmed up.

FYI my connector is black with white in-layed plastic segment. Wire colors are white, green-striped, green & pink.

I was unable to get green wire removed from connector to determine postive ("a/c off "in defrost) results or negative (does not turn a/c off or some other issue) result.

Does anyone know how do this on 09+ models.

 

I think another member on here tried to remove a wire in the harness similar to the 05-08 mod and it messed up his HVAC. I would like to know how to disable it in my 09.

 

Reading through the manual it appears that if you put the vents to your feet some air would also go to your windshield w/o A/C. I will have to test when i get home. My manual also says a/c not on with defrost, so maybe toyota just types what they feel like.

 

Air to feet does not push enough air to defog your front window. And I confirm, a/c cycles on/off when in defrost mode.

 

The "feet only" mode is exactly what I use to defrost the windshield. Turn the fan on high and not only does it defrost the windshield, but also the side windows as well. Not to mention it seems to warm the whole cab up a bit faster. I *never* use the windshield modes unless it's so humid out that I need to AC to keep the windows from fogging on the inside.

 

I had no luck intrying to remove the green wire from the plastic connector by using a pin or paperclip. It easily came out when I used small needle nose pliers to reach into the clip and grab on to the metal connector clip and pull it out from behind.

 

Thanks for the mod.

I just did it. The hard part is getting the green wire clip to come out of the connector. I tried everything for half an hour and finally gave up and cut the f'n wire.

 

Man this is an awesome mod. Something I hate about my 09 Tacoma. I like when the operator is able to take control of the HVAC system. Anyone have any luck yet with the 2009 wiring?

 

Bump for 2010 trucks as well.

 

Interesting post. I wont be doing it on mine though.

I rarely use the defrost,
A. because I park in the garage
B. because I drive with the AC on in the winter with the heat which keeps ALL the windows from fogging without having to use the defrost. I don't really notice much of a difference in the temp of the air because the AC knows when to come on/off to keep the unit from freezing up.

The reduction is gas mileage is not that noticeable to me personally.

I have been doing this in all the vehicles I have driven, I learned it from my dad who has been doing it all his life. My girlfriend thought I was crazy when I told her to run the AC in the winter but she quickly changed her mind when she realized she didnt have to use the defroster, and had to have a leaking AC line replaced two summers in a row due to a bad seal from not running the AC all winter.

You should run your AC often to keep the seals lubed as someone already stated

 

Why does the recirc button kick out shortly after you
turn it on? Even if the fan isnt on and it is one floor only
position?
2010 4cyl AC Base model

 

The 2009 models introduced logic into the defroster which affects the circulation mode.

I believe your answer can be found in this post here

 

When in defrost the AC is on in my 09. I know this since I've wired my electric fan into the AC compressor signal line. When in defrost the compressor cycles on and off as needed depending on the temp selected.

 

I'm really having trouble getting the wires out, can someone that has done this mod take a close up picture of the metal piece on the end of the wire?

I'm trying to test this out for the 09+ but I don't want to rip out the wires in case it won't work.

 

I have a 2010 i disconnected the green wire, the ac would come on all the time if the fan was on so i then disconnected the green with stripe and reconnected the green and the selector switch would not work. Has any one found out how to run the defrost and not the ac on a 2010?

 

I just completed this mod on my 2010 Taco. I too couldn't release the green wire from the connector, and it finally broke after struggling with it for like an hour. The A/C then turned on 100% of the time as the other 2009/2010 owners have commented. And the recirculate light/function was then disabled.

But I also found the fix. Measuring the voltage on the green wire coming from the servo motor/connector, I noticed it only read 0V when in defrost-only mode. Turning the air-vent-mode dial to any other position caused it to read greater than 0V. Turning to the vent-only position caused it to read +12V. So I simply tied the green wire going to the A/C amplifier to +12v and all works great now! I can now toggle both A/C and recirculate during any functionality (A/C and recirculate are no longer hard-tied during defrost modes).

Details:
1) Cut green wire. Tie off the side coming from the servo motor/connector so it doesn't short to anything, it'll never be needed again.
2) The other end of the green wire goes to the A/C amplifier per the schematics I found on this site. Tie this end to +12V. The pink wire happens to be +12V. So just connect this end of the green wire to the pink wire and you're done!

Thanks again for posting this fantastic mod. I wouldn't have figured this out any other way.

 

First, welcome to TW!

Second, post pictures! You may just become a TW hero.

 

Yes, post pictures please!!

 

As requested, I've attached pics to my previous reply above.

Thank you for the great compliment Juggernaut. I felt it's the least I could do for all you subscribers considering how much information you generously lend out!