Disable automatic AC with Defogger

[Wade-0]

If you don't know this already, the AC comes on when you have the dial on DEFOG or DEFOG+HEATER (the two rightmost positions). There is no way to turn it off. This mod will disable that "feature":

You will need:

1. Phillips screwdriver
2. Soldering iron (or wire snips)
3. Electrical tape


If you remove the stereo and loosen the screws on the HVAC control pod, you will see a rocker switch that is activated when the dial is turned to DEFOG or DEFOG+HEATER. It's circled in red:



If you look at the underside of the switch, there are two purple wires soldered to the leads (one is disconnected in my photo):



Hold a soldering iron to one of the leads and pull on the purple wire until it pops off. Tape the end of the wire off and reassemble the console. Now the AC only turns on when you push the button.

If for some reason you want it back later, just resolder the purple wire to the switch lead.

**Note: I never removed the HVAC pod, I just pushed it up so I could reach the switch with my soldering iron. I have no idea how you get that pod out without breaking anything, so don't try.

[FUNKED1]

[KurleeDaddeeWRX]

That is awesome. A+ post. I will bookmark this one too.

Anyone know why it is wired that way, so the A/C comes on while the DEFOG is on?

Kurlee Daddee
(THE ORIGINAL)

[Wade-0]

Originally posted by KurleeDaddeeWRX
That is awesome. A+ post. I will bookmark this one too.

Anyone know why it is wired that way, so the A/C comes on while the DEFOG is on?

Thanks! It helps the defogger by dehumidifying the air, but the manual only says it comes on with the defogger. After a lengthy discussion in the pet peeves thread, it was revealed that it also comes on in the defogger+heat position, which is what I use 90% of the time. So I decided to pop it open and see what I could find. It was actually a lot easier than I thought it was going to be.

[KurleeDaddeeWRX]

So I am asssuming that the defogger works fine and clears up the window without the help of the A/C? I also use heat/defogger at the same time. But, everytime I get out of the car when the turbo timer is running, and I foget to turn off the heater while the defogger is on, the A/C kicks in and makes my alarm go off.

I might try this one. Very good post.

Kurlee Daddee
(THE ORIGINAL)

[Wade-0]

Originally posted by KurleeDaddeeWRX
So I am asssuming that the defogger works fine and clears up the window without the help of the A/C? I also use heat/defogger at the same time.

It depends on the humidity. You can still turn on the AC to help defog, you just have to push the button now. I prefer it that way, since I can now control when it's on instead of it always being on. I use the defog+heat setting most of the time because I like the airflow it provides, now I can run it that way without being forced to run the AC.

[dark_rex]

anyone who's owned a japanese car knows the nightmare of dealing with fogged windows.

the A/C coming on is an attempt to combat that. if you have the heat on with the defogger, the windows won't clear as well.

to clear your windows quickly, simply put the vent on either outside air, or halfway b/w in and out, and turn back the heat a bit.

disconnecting the A/C from your defogger will make it more difficult to clear your windows in 90% of the circumstances. basically, my point is you'll need to manually enable the A/C to quickly clear your windows.

dR

[glepko]

Ummm....mine doesn't work like that, never has. I've always had to turn the A/C on when I want to use it with defrost. Bought the car off the truck so to speak.

[beastcivic]

Originally posted by glepko
Ummm....mine doesn't work like that, never has. I've always had to turn the A/C on when I want to use it with defrost. Bought the car off the truck so to speak.

Unless your car is different from every other person I've talked to it does come on, the light won't illuminate, but the AC is running. Try using the 'defrost' mode in the summer heat. You'll notice the air coming in is nice and cool compared to if you switch it to the other vent settings that are non-defrost.

[Wade-0]

This is why it was such a drawn out discussion and I finally tore into the dash to answer the question once and for all. Apparently you can't notice the AC compressor coming on at fast idle, which is when most people are going to use their defogger anyway.

If you still don't believe, then do this simple test. Open the console and watch the dial as you turn it to defog+heat and defog. You will see the switch being activated by a raised portion of the dial. You can actually reach in and close the switch with your hand and hear the compressor kick on once the car is warmed up.

[SubieGalRacing]

ummmmmmmmm

why would you want to disable this?

Jamie

[dark_rex]

Originally posted by SubieGalRacing
ummmmmmmmm

why would you want to disable this?

Jamie

exactly. you probably wouldn't.

[Wade-0]

Originally posted by SubieGalRacing
ummmmmmmmm

why would you want to disable this?

Jamie

It's pretty obvious, but I guess it needs reiterating: so you can run your defogger or defogger+floor without the AC turning on automatically.

[beastcivic]

Exactly. I prefer to have the air flowing through the cabin up the window and through the car instead of at my body/face. But I don't really want to run the A/C the whole time.

[is2scooby]

Yep - this is a great mod!

Plus when you're at the race track - you can use the defroster/heater to pull heat out of the engine without robbing power and dropping water all over the track surface from the evap. core drain tube!