DIY: Unlink A/C from Defroster

[barryware]

when the compressor is allowed to run based on the status of the A/C switch or the position of the air selector knob, it won't run for long anyway in the winter. The compressor runs and cycles on and off based on refrigerant pressure.

When it is cold out, the compressor may start but because the refrigerant pressure will be too low based on temperature to continue to run, it will shut itself off. I really do not see the need to disable the operation based on the position of the selector knob.

If it is warm enough, you may want the compressor to run and aid in defogging the windows. If it is cold enough and heat alone will do the job, the compressor isn't going to run anyway.

[CTScott]

Originally Posted by barryware

when the compressor is allowed to run based on the status of the A/C switch or the position of the air selector knob, it won't run for long anyway in the winter. The compressor runs and cycles on and off based on refrigerant pressure.

When it is cold out, the compressor may start but because the refrigerant pressure will be too low based on temperature to continue to run, it will shut itself off. I really do not see the need to disable the operation based on the position of the selector knob.

If it is warm enough, you may want the compressor to run and aid in defogging the windows. If it is cold enough and heat alone will do the job, the compressor isn't going to run anyway.

I find that even in below freezing temperatures that the compressor engages far more frequently than you would expect it to when running in defog mode.

[rick996]

I'm glad bronsin posted to this thread recently. I hadn't seen it before. I just did the tab removal. It took just 10 minutes. I never liked the link of the defroster to the A/C. Thank you stran for posting the original hack (3 years ago).

[A-Dingo-Ate-My-Baby]

Originally Posted by rick996

I'm glad bronsin posted to this thread recently. I hadn't seen it before. I just did the tab removal. It took just 10 minutes. I never liked the link of the defroster to the A/C. Thank you stran for posting the original hack (3 years ago).

I am not sure I understand this. My AC turns on with a button press.

2010 Yaris 5 door US spec with manual temp control knobs.

are you saying that the A/C turns on by itself in certain modes ?
my A/C light will only go on when I press the button

[rick996]

Originally Posted by A-Dingo-Ate-My-Baby

2010 Yaris 5 door US spec with manual temp control knobs.

are you saying that the A/C turns on by itself in certain modes ?
my A/C light will only go on when I press the button

Yes. Whenever you are in one of the 3 defrost modes (full or split). The light doen't come on. All modern cars that I know of do this. It makes the A/C last longer to run the A/C compressor once in a while during the winter. I will put the A/C on manually to accomplish this, but only when I am going down a long hill using DCFO.

[A-Dingo-Ate-My-Baby]

Originally Posted by rick996

Yes. Whenever you are in one of the 3 defrost modes (full or split). The light doen't come on. All modern cars that I know of do this. It makes the A/C last longer to run the A/C compressor once in a while during the winter. I will put the A/C on manually to accomplish this, but only when I am going down a long hill using DCFO.

holy crap you are right. I just tested it and watched the a/c engage
because I didn't really believe it, and the manual says 'if so equipped' and
since I got an almost rock bottom base model, I was convinced there were no
freebies here. the 4runner always goes to full a/c when you press defog but the
a/c lights up too...yaris doesn't light but compressor certainly starts

[swede]

I tried this mod today, I couldn't believe how easy it was to pull the dash apart to get to it. Everything just popped out and popped back in with ease, no screws or nothing. Just seemed a lot easier than previous cars that I've owned.

anyways I took some pictures and didn't find the wiper arm, maybe somebody can point it out to me. Hopefully the pictures will show it. I have a feeling that maybe I didn't go far enough.

1. Remove dash pieces
2. Pull AC knob out, be careful not to break the tabs


3. Pull backing off the unit, again be careful not to break the tabs