DIY: Unlink A/C from Defroster

[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

[swede]

here are some pictures of the micro switch. Didn't have AC in my last car and didn't have too much trouble without it, but I am still considering soldering it off instead of breaking it.

[CTScott]

You might as well desolder it, since you are in there. Chances are that you will never bother to put it back, but that way you have the option.

[lilpusher]

hey there people. Yes the ac is a pump and robs power etc. however there is a really good reason it turrns on with the defrost. There is oil suspended in your refrigerant that keeps all those tight clearance parts in your expensive ac compressor running smooth. when your compressor doesn't run for say 8 months of the year the oil seeps down and parts seize up. when the pump blows you get to replace everything at a huge cost the engineers are smart so to prevent you from replacing your ac system every year or so they attached a trigger wire to your defrost to keep things lubed up. cheers.

[A-Dingo-Ate-My-Baby]

Originally Posted by lilpusher

hey there people. Yes the ac is a pump and robs power etc. however there is a really good reason it turrns on with the defrost. There is oil suspended in your refrigerant that keeps all those tight clearance parts in your expensive ac compressor running smooth. when your compressor doesn't run for say 8 months of the year the oil seeps down and parts seize up. when the pump blows you get to replace everything at a huge cost the engineers are smart so to prevent you from replacing your ac system every year or so they attached a trigger wire to your defrost to keep things lubed up. cheers.

well let me be the one to say this is BS

The defrost mode goes to A/C, BECAUSE

most people track snow and slush into the vehicle, and in the
winter the inside of a car becomes really humid, and often, ice forms
on the inside of the window as well as the outside in winter.

So, defrost mode activates A/C to assist taking care of this problem
of frost on the inside of the glass.

[bronsin]

True enough moisture inside the car makes trouble and the AC with defrost fixes it fast.

And also I would want to cycle my AC once in a while to keep things lubed for long life.

But having the AC slaved to defrost means running the AC without reason plenty of times.

Which wastes fuel.

Toyota I can decide for myself when to use the AC with defrost thankyou very much.

That goes for all their other idjit "protect the driver from himself" things like ABS, traction control, press clutch to start etc etc etc.

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

well let me be the one to say this is BS

The defrost mode goes to A/C, BECAUSE

most people track snow and slush into the vehicle, and in the
winter the inside of a car becomes really humid, and often, ice forms
on the inside of the window as well as the outside in winter.

So, defrost mode activates A/C to assist taking care of this problem
of frost on the inside of the glass.

[lilpusher]

chastised on first post, love it. so you've heard of Holden down in OZ right? Bet you $10 the AC pumps in their cars periodically cycle with defrost. Not a lot of snow to contend with down there. BUT ac does indeed help with humidity. Maybe you can enlighten me since I'm new to this model. does the defrost setting on the yaris put the hvac system into recycle as opposed to fresh air?

[rick996]

+1

Originally Posted by bronsin

True enough moisture inside the car makes trouble and the AC with defrost fixes it fast.

And also I would want to cycle my AC once in a while to keep things lubed for long life.

But having the AC slaved to defrost means running the AC without reason plenty of times.

Which wastes fuel.

Toyota I can decide for myself when to use the AC with defrost thankyou very much.

That goes for all their other idjit "protect the driver from himself" things like ABS, traction control, press clutch to start etc etc etc.

[edgardhe]

I did this mod yesterday. It was more tricky than I wanted. I'm pretty new at this though. I tried to desolder the switch and after some fenangling I got it, but I had turned the gears and they were out of alignment for reassembly. I turned the gears until I heard the switch engage and that should have marched the selector at the top of the dial where the defrost turns on. It didn't seem to match though and after a few turns, I heard a crackle and the metal bit of the switch fell out of the assembly. So much for the soldering. Without having to align the switch it was easy to get everything back together once I figured out that the notch on the small gear faces the wall of the assembly. Live and learn. I'm thankful for this forum. I was leaving my car in defrost so the compressor was pretty much running all the time.

[spookybathtub]

Fantastic, thanks so much for posting this! I desoldered the switch and the whole job took about 10 minutes. I wish I had discovered this years ago.