dont want ac compressor to kick on

[3bears]

I am not certain, but if the relay is disabled I don't think the a/c button will engage the clutch. This may well disable the a/c altogether.

The simplest method is to unplug the wires that are switched by the "defog" or "defog/ feet" position of the control. On my 2000 with the basic heat this is the pair of blue wires described by Charlie and myself.

this is most likely the route I will take. then I can use the ac button when needed for "extra" defrost...and exercise the compressor occasionally, like exercise the 4wd like we are supposed to in off seasons.

if it helps with mpg...that's good...this time of year I go from 18mpg to 11 or 12...in part because I have to let it warm up for a while outside even though I have block, pan and tranny heaters and im in 4wd all the time

 

[phattyduck]

well to be honest...no
but it sounds like it is and the engine idle goes up and down when it sounds like it kicks in. jumps from just under 700rpm to about 1100 rpm

There is a thermistor for the AC system that should engage/disengage the AC compressor clutch when the AC is "ON" (button depressed or either defrost setting selected). The compressor shouldn't engage until the air coming past the AC evaporator is above freezing - the thermistor is there to avoid freezing up the evaporator core in humid conditions. The AC amplifier may still turn on the AC compressor for periods of time despite the temp though - I haven't tested that.

-Charlie

 

[alumarine]

Had a chance to test mine.
At 28F the compressor cycles occasionally.
At 3F compressor never comes on.

 

[nevada]

just interrupt the circuit at the compressor clutch. wire in a switch at that connection. you will have instant and ultimate control at the flip of a switch.

 

[3bears]

So it depends on the year and if you have the electronic or manual climate control. But on my 2000 I disabled the auto a/c with defrost. You just have to unplug an electrical connector right behind the climate control bezel. Best part is you can still push the A/C button if you need extra help defrosting. Heres a picture

ok so mine is a 2000 with the dial slide havac like you have pictured, however, I went into it yesterday and there is no easy to find plug behind it. and not one with 2 blue wire did not want to start removing screws as it looks like it is mounted behind dashboard.
so closed it up....ran out of time...today I guess I will go for the relay behind glove box

 

[3bears]

Had a chance to test mine.
At 28F the compressor cycles occasionally.
At 3F compressor never comes on.

well I could not get to the wire mentioned in one of the other replies..today if time I will pull the relay..
if I don't I will try to see if it does indeed cycle on in really chilly weather. yesterday it was above 20 and it was kicking on all the time. Today it is already
above 20 and it was cycling when I went to take my grandkids to school

maybe just need to get used to being in a chilly car when it is like minus temps outside

 

[phattyduck]

ok so mine is a 2000 with the dial slide havac like you have pictured, however, I went into it yesterday and there is no easy to find plug behind it.

Check the picture on the first page of the thread. You'll need a pick or tool to remove the plug, but you don't have to remove the HVAC controls at all.

-Charlie

 

[3bears]

Check the picture on the first page of the thread. You'll need a pick or tool to remove the plug, but you don't have to remove the HVAC controls at all.

-Charlie

ok...thats a different picture from the picture on the first page. from the picture on first page I was thinking it was more visible...male and female and towards the upper back..i did kind of see a plug with wires going to the lower right corner of the heater controls and maybe a bit difficult to get to.The colors looked different too...but that could have been poor lighting. I was afraid to pull it as it looked like it would be difficult to put back if I was wrong...and like I said...I was looking for something to the upper right and more visible

 

[rallypoint_1]

For me it was easier to pull AC control panel. Just a few screws. I couldn’t get my fingers in there with it on.

 

[seen20]

Its not always as easy to see as the pictures make it out to be. I remember mine being kinda hard to get to. Also its not necessarily a blue wire. Pretty sure mine actually looked like this. It should be there though if you have a 2000 with the dial controls. White connector on the right side of the controls

 

[3bears]

Its not always as easy to see as the pictures make it out to be. I remember mine being kinda hard to get to. Also its not necessarily a blue wire. Pretty sure mine actually looked like this. It should be there though if you have a 2000 with the dial controls. White connector on the right side of the controls

thanks for that picture..that I saw. The other thing that cofused me was that in an earlier post ( not by you) it said blue wires. Since I did not see blue wires and not at top of controls...it thought....nope not it...don't see it...not messing with it.

will try to go back into it today and get that plug

thanks everyone else too for your help

 

[phattyduck]

Wire colors are always referenced to the harness on the truck, not the 'item' side of the plug. So, the yellow / black wires there are the wires that go in to the switch area on the control panel and would not be called out on the diagrams.

The plug is on the back right bottom corner of the control panel.

-Charlie

 

[3bears]

Wire colors are always referenced to the harness on the truck, not the 'item' side of the plug. So, the yellow / black wires there are the wires that go in to the switch area on the control panel and would not be called out on the diagrams.

The plug is on the back right bottom corner of the control panel.

-Charlie

thanks for your help on this

 

[Riceye]

I had to dig a little to find Charlie's post about this. When I disabled my defrost a/c I did not take any pics. My harness wires to the plug were blue and blue/white just as in the pic below. It would appear the wire color and plug configuration of some units differed.

Updated scangauge mount installed (from Paranoid Fabrications), bought used from TonyB66. He had already installed a backing strip to hold the Scangauge up in place. I added velcro to the back and a bit of foam to hold it snuggly in place:

My previous mount was in the same place, just a bit more ghetto... two bits of aluminum bent so they hug the Scangauge:

While I had the dash open, I also disabled the auto-AC on defrost. My favorite air setting for most situations is defrost - you can get plenty of air movement without anything blowing in your face (one of my few pet peeves about the 4Runner - you can't point the AC vents low enough to stay out of your face!). The only problem is the AC comes on in this mode to dry the air for clearing the windshield - which is almost never needed in California.

You just need to unplug this two pin connector on the back right corner of the AC controls. This only works on the manual AC trucks. It only affects the two defrost settings, and otherwise everything works normally. I'm smart enough to turn on the AC if I need extra de-humidifying at some point... I did the same thing on my '03 WRX with great success. My Camry doesn't turn the AC on automatically with defrost, so no worries there.

-Charlie

 

[3bears]

I had to dig a little to find Charlie's post about this. When I disabled my defrost a/c I did not take any pics. My harness wires to the plug were blue and blue/white just as in the pic below. It would appear the wire color and plug configuration of some units differed.

yep , thanks for your pictures..mine is a 2000 SR5 also...but I guess there can be color changes..mine is actually a early 2000.....build date 1/2000..so maybe some things changed.
I have found other small differences in my 4runner....
im gonna tear back into it...hopefully today

thanks again for your help

 

[3bears]

thanks to all who helped...that is what makes this forum so valuable. I had to pull the headunit ( stereo) to get access to the plug due to my big clumsy fingers..and get a dental pick in to get it to bust loose...but got it.
now we will see how it helps in sub zero temps....has to help some
even if not cycling in sub zero temps...if cycling at all when she has to sit and warm up..it has to help with mpg

thanks again guys...girls...folks