Toyota Yaris Forums - Ultimate Yaris Enthusiast Site
 

 


 
Go Back   Toyota Yaris Forums - Ultimate Yaris Enthusiast Site > Technical Forums > DIY / Maintenance / Service
  The Tire Rack

Reply
 
Thread Tools Display Modes
Old 11-17-2008, 07:30 PM   #1
stran
 
Drives: '07 Yaris 3D HB Auto
Join Date: Jul 2007
Location: Cal
Posts: 44
Help Needed: Unlink A/C to Defroster

I don't like the way how the A/C has to be on when I turn on the front defrosters. I think there are two ways to fix this: fake out the detector switch so the car doesn't know you turned on the defroster, or kill the circuitry that automatically turns on the A/C.

In case you don't have the Factory Repair Manual Handy:
http://www.etimago.com/yaris/repairmanual/EWD.pdf
http://www.etimago.com/yaris/repairm...nditioning.pdf

This might get a little technical:
Option 1
One guest is that the switch could be inside the control knob itself, and the signal could be turned off by shorting the signal wire or soldering in a resistor. Take a look at page 245 of the Air Conditioning manual for more info about this. Or there could be a switch in the air damper that controls flow to the front defroster. See page 10.

Option 2
The Electrical Wiring Diagram Manual (filename: EWD.pdf) on page 239, 240, and 330 mentions "Defroster Mode Detection SW" in the context of air conditioning. SW means switch. The problem is that I don't know where this switch is physically located in the car. The diagram on page 50 and 52 might help answer this question but I can't put the two together.

Any help is appreciated, and I know I'm not the only person who wants to get rid of this.
stran is offline   Reply With Quote
Old 11-17-2008, 07:40 PM   #2
TheRealEnth
Beast
 
TheRealEnth's Avatar
 
Drives: 2007 Blz Blu LB
Join Date: Oct 2008
Location: Miami, FL
Posts: 1,365
Send a message via AIM to TheRealEnth
i really dont mind?
__________________

One you've taken a yaris for a spin, there's no turning back.
Its a Chao!!!
TheRealEnth is offline   Reply With Quote
Old 11-17-2008, 07:48 PM   #3
IllusionX
It's the illusion you see
 
Drives: 07 Yaris Sedan Aero
Join Date: Oct 2006
Location: Brossard, QC
Posts: 3,888
there IS a switch inside the knob that activates the compressor AND THE BUILT IN HEATER...

you do not really want to get beyond that that in messing around the wires...
IllusionX is offline   Reply With Quote
Old 11-17-2008, 08:28 PM   #4
auxmike
 
auxmike's Avatar
 
Drives: 2008 HB, A/T, Power W/L/M
Join Date: Oct 2008
Location: LI, New Yawk
Posts: 2,063
What about in the deep of winter, will the A/C still kick on?
auxmike is offline   Reply With Quote
Old 11-17-2008, 09:04 PM   #5
CTScott
ULTIMATE
 
CTScott's Avatar
 
Drives: 09 5dr LB, 2x 08 3dr LB
Join Date: Oct 2008
Location: USA, CT
Posts: 13,460
Quote:
Originally Posted by stran View Post
I don't like the way how the A/C has to be on when I turn on the front defrosters. I think there are two ways to fix this: fake out the detector switch so the car doesn't know you turned on the defroster, or kill the circuitry that automatically turns on the A/C.

In case you don't have the Factory Repair Manual Handy:
http://www.etimago.com/yaris/repairmanual/EWD.pdf
http://www.etimago.com/yaris/repairm...nditioning.pdf

This might get a little technical:
Option 1
One guest is that the switch could be inside the control knob itself, and the signal could be turned off by shorting the signal wire or soldering in a resistor. Take a look at page 245 of the Air Conditioning manual for more info about this. Or there could be a switch in the air damper that controls flow to the front defroster. See page 10.

Option 2
The Electrical Wiring Diagram Manual (filename: EWD.pdf) on page 239, 240, and 330 mentions "Defroster Mode Detection SW" in the context of air conditioning. SW means switch. The problem is that I don't know where this switch is physically located in the car. The diagram on page 50 and 52 might help answer this question but I can't put the two together.

Any help is appreciated, and I know I'm not the only person who wants to get rid of this.

I looked at the EWD. To disable it you would need to cut a trace on the printed circuit board for the AC switch assembly. I would have to pull one apart to figure out which trace, but the other option is to replace the switch. The EWD indicates that there is one "w/ Defroster Mode Detection SW" and one "w/o Defroster Mode Detection SW".
CTScott is offline   Reply With Quote
Old 11-18-2008, 03:19 AM   #6
Revsson
 
Drives: 2009 Meteorite Metallic LB MT
Join Date: Oct 2008
Location: Southeast Wisconsin
Posts: 810
Quote:
Originally Posted by stran View Post
I don't like the way how the A/C has to be on when I turn on the front defrosters. I think there are two ways to fix this: fake out the detector switch so the car doesn't know you turned on the defroster, or kill the circuitry that automatically turns on the A/C.

In case you don't have the Factory Repair Manual Handy:
http://www.etimago.com/yaris/repairmanual/EWD.pdf
http://www.etimago.com/yaris/repairm...nditioning.pdf

This might get a little technical:
Option 1
One guest is that the switch could be inside the control knob itself, and the signal could be turned off by shorting the signal wire or soldering in a resistor. Take a look at page 245 of the Air Conditioning manual for more info about this. Or there could be a switch in the air damper that controls flow to the front defroster. See page 10.

Option 2
The Electrical Wiring Diagram Manual (filename: EWD.pdf) on page 239, 240, and 330 mentions "Defroster Mode Detection SW" in the context of air conditioning. SW means switch. The problem is that I don't know where this switch is physically located in the car. The diagram on page 50 and 52 might help answer this question but I can't put the two together.

Any help is appreciated, and I know I'm not the only person who wants to get rid of this.
It doesn't say it in your profile, but I assume that since you joined in 2007,
that you drive an '07 LB?
Just trying to clarify if there can possibly be any difference in the model
years for the A/C.
Revsson is offline   Reply With Quote
Old 11-18-2008, 05:18 AM   #7
jambo101
 
jambo101's Avatar
 
Drives: yaris 08 sedan
Join Date: Oct 2008
Location: Montreal Canada
Posts: 1,286
Quote:
Originally Posted by stran View Post
I don't like the way how the A/C has to be on when I turn on the front defrosters. .
I dont like it either,seems like a waste of energy,all previous cars i've owned never had air and i never had a defrost problem, but what is needed to defeat this operation looks like more trouble than its worth so i'll just crank up the heat a little more to overcome the permanent air when in the defrost mode
jambo101 is offline   Reply With Quote
Old 11-18-2008, 07:32 AM   #8
floydisrock
73 Centurion droptop 455
 
floydisrock's Avatar
 
Drives: 2009 S Sedan
Join Date: Oct 2008
Location: Phoenix Arizona
Posts: 64
The ac compressor in a vehicle should be run to prevent clutch and bearing problems.
Every Car I've owned mentions running the ac at least once a month.
I'm guessing they just let the compressor run,so they don't have so ,many warranted a/c compressors to replace.
I wouldn't worry about the few cents your going to save disconnecting the unit,I would worry about replacing a $1000 a/c compressor.
__________________
"THIS SITE HAS BEEN HACKED BY www.bimmerfest.com. YOU FUCKERS!"
floydisrock is offline   Reply With Quote
Old 11-18-2008, 08:13 AM   #9
jambo101
 
jambo101's Avatar
 
Drives: yaris 08 sedan
Join Date: Oct 2008
Location: Montreal Canada
Posts: 1,286
My winter setting is the defrost/floor position for the entire winter so i guess i have no other option than to have the air running all winter whether i like it or not.
jambo101 is offline   Reply With Quote
Old 11-18-2008, 08:57 AM   #10
eTiMaGo
vroom vroom
 
eTiMaGo's Avatar
 
Drives: lil red 5-door
Join Date: Sep 2006
Location: Bangkok, Thailand
Posts: 7,744
Send a message via AIM to eTiMaGo Send a message via MSN to eTiMaGo Send a message via Yahoo to eTiMaGo
winter or not, I believe the main reason for the AC kicking in is to dry out the air to help with the defrosting/defogging itself?
__________________
The price of freedom of religion, or of speech, or of the press, is that we must put up with a good deal of rubbish.
- Robert Jackson


Bye bye 1NZ...
eTiMaGo is offline   Reply With Quote
Old 11-18-2008, 09:08 AM   #11
IllusionX
It's the illusion you see
 
Drives: 07 Yaris Sedan Aero
Join Date: Oct 2006
Location: Brossard, QC
Posts: 3,888
Quote:
Originally Posted by jambo101 View Post
My winter setting is the defrost/floor position for the entire winter so i guess i have no other option than to have the air running all winter whether i like it or not.

you don't NEED to run with defrost/floor all winter long... put it back to the floor only when the front window is defogged.
IllusionX is offline   Reply With Quote
Old 11-18-2008, 10:49 AM   #12
jambo101
 
jambo101's Avatar
 
Drives: yaris 08 sedan
Join Date: Oct 2008
Location: Montreal Canada
Posts: 1,286
Quote:
Originally Posted by IllusionX View Post
you don't NEED to run with defrost/floor all winter long... put it back to the floor only when the front window is defogged.
Tried that and the windows start fogging up again,seems some airflow is constantly needed on the window to keep it fog free' but just warm air will do the job once the car is at operating temperature,at that point the air is no longer needed but there is no way to turn it off and still have airflow over the window.
jambo101 is offline   Reply With Quote
Old 11-18-2008, 04:05 PM   #13
stran
 
Drives: '07 Yaris 3D HB Auto
Join Date: Jul 2007
Location: Cal
Posts: 44
Quote:
Originally Posted by Revsson View Post
It doesn't say it in your profile, but I assume that since you joined in 2007,
that you drive an '07 LB?
Just trying to clarify if there can possibly be any difference in the model
years for the A/C.
I have a '07 hatchback.

PS How do I subscribe to a thread if I forget to do it when I post?
stran is offline   Reply With Quote
Old 11-18-2008, 04:09 PM   #14
stran
 
Drives: '07 Yaris 3D HB Auto
Join Date: Jul 2007
Location: Cal
Posts: 44
Quote:
Originally Posted by IllusionX View Post
there IS a switch inside the knob that activates the compressor AND THE BUILT IN HEATER...

you do not really want to get beyond that that in messing around the wires...
Except the connection to the heater is probably via a mechanical linkage. I know that the vent knob operates via a mechanical linkage. With the car off and there's no power, you can still switch between the vents. On luxury cars I've driven before, the soft buttons activate a little motor that open and closes the damper that only works when the car is on.
stran is offline   Reply With Quote
Old 11-18-2008, 04:11 PM   #15
stran
 
Drives: '07 Yaris 3D HB Auto
Join Date: Jul 2007
Location: Cal
Posts: 44
Quote:
Originally Posted by jambo101 View Post
Tried that and the windows start fogging up again,seems some airflow is constantly needed on the window to keep it fog free' but just warm air will do the job once the car is at operating temperature,at that point the air is no longer needed but there is no way to turn it off and still have airflow over the window.
agreed. i also like having warm air diffused instead of concentrated at my face or feet, and the best way to do that is through the defroster vents.
stran is offline   Reply With Quote
Old 11-18-2008, 04:13 PM   #16
CTScott
ULTIMATE
 
CTScott's Avatar
 
Drives: 09 5dr LB, 2x 08 3dr LB
Join Date: Oct 2008
Location: USA, CT
Posts: 13,460
Quote:
Originally Posted by stran View Post
I have a '07 hatchback.

PS How do I subscribe to a thread if I forget to do it when I post?
07 and 08 use the same ribbed knob switches and 09 has knurled knobs. I looked at the EPC, but can't figure out from the wording, which switch is the one which doesn't automatically turn on the AC when in defogger mode.

Go to User CP (control panel) and click on list subscriptions, then you can select the notification method for threads that you have posted in.
CTScott is offline   Reply With Quote
Old 11-18-2008, 04:21 PM   #17
CTScott
ULTIMATE
 
CTScott's Avatar
 
Drives: 09 5dr LB, 2x 08 3dr LB
Join Date: Oct 2008
Location: USA, CT
Posts: 13,460
Quote:
Originally Posted by stran View Post
Except the connection to the heater is probably via a mechanical linkage. I know that the vent knob operates via a mechanical linkage. With the car off and there's no power, you can still switch between the vents. On luxury cars I've driven before, the soft buttons activate a little motor that open and closes the damper that only works when the car is on.
The knob that changes where the air is blowing does so by cable as you mention. Here are some pictures of what the back of the switch assembly looks like:





From this thread about changing the bulbs:
http://www.yarisworld.com/forums/sho...light=led+dash

If you look at the close-up picture above the outer knob turns a plastic gear. I would bet that there is a boss on the gear that bumps a switch that parallels the AC switch. If so, you could just clip the boss...
CTScott is offline   Reply With Quote
Old 11-18-2008, 04:37 PM   #18
jambo101
 
jambo101's Avatar
 
Drives: yaris 08 sedan
Join Date: Oct 2008
Location: Montreal Canada
Posts: 1,286
Seeing as you have it all apart anyway can you give us a pic of the cam/boss that activates the air while in defrost mode? dont know why Toyota couldnt have given me the option of defrost with air on or off,like its only a matter of pushing a button if i want the air on.
jambo101 is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Gas mileage and A/C Chaad32 General Yaris / Vitz Discussion 18 01-29-2009 04:31 PM
Do u guys set to Fresh Air for A/C? hans_fh General Yaris / Vitz Discussion 17 06-12-2007 03:24 PM
A/C & Aftermarket intake KSIbucky DIY / Maintenance / Service 2 03-26-2007 09:08 PM
A/C smelling weird? Yaris_PR General Yaris / Vitz Discussion 11 08-04-2006 08:26 AM


All times are GMT -4. The time now is 01:08 PM.




YarisWorld
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.