How-To: Disabling Automatic A/C - Defrost modes

Would there be a built in software solution. I know on my 2001 civic, holding a couple buttons while turning the ignition on disabled it.
 

Dexter

Banned
Contributor
^ Doubt it. I dont think the control board is that intelligent.

eting_pro5: put it on recirculated air. this closes the fresh air door and you will not feel any more blowing. it feels like the fans are blowing when on "0" but when you are moving it just fresh air coming i.
 

loccusst

Experianced noob
:
2003 Yellow Mazda Protege5 Autostick
I did this today while in the middle of working on my 95 contour (my winter beater). It took my all of about 20 min. to do, excellent right up and pics were definately the reason why it went quick. My contour also turns on the ac when you have the settings to defrost. Must be a Ford/Mazda thing.
 

blynd_spy

i've nothing to type here
:
2003 LX
led out?

does doing this mod cause the recirculating air led to not come on? i changed the leds at the same time, but the led isnt burnt and the circuit board looks fine..
 

blynd_spy

i've nothing to type here
:
2003 LX
nevermind, ifigured out my mistake.... the solder points for the led were touching... (hand)
 

2K3 MSP

Contributor
:
Spicy Orange MSP #1287
So, my main concern about this is whether this will actually help me save a little gas. Assuming that since the A/C is on, it wastes gas while I'm trying to de-fog my windows right? So, if I disconnect the A/C as shown, will I still be able to de-fog the windows without using the A/C??
 

blynd_spy

i've nothing to type here
:
2003 LX
you can still use defrost with out the a/c... however, it will not defrost as fast since the a/c acts as a humidifier and for reasons i dont want to look up causes the window to de-fog faster.
Im still getting used to it since ive only driven my car once since i did it so hopefully someone will jump in....

hope that helps
 

2K3 MSP

Contributor
:
Spicy Orange MSP #1287
As long as it works, that's all I need. I just hate using my A/C when defogging the windshield.
 

Dexter

Banned
Contributor
Hey zap, got a question. you think that just closing the switch is sufficient enough to turn on the AC (as if i had pressed the A/C button on the console?)
 

ZapWizard

Electro-modder
Dexter said:
Hey zap, got a question. you think that just closing the switch is sufficient enough to turn on the AC (as if i had pressed the A/C button on the console?)
I beleave so.
There are two lever switches:
One turns on the A/C
The other activates the fresh air circuit.
 

loccusst

Experianced noob
:
2003 Yellow Mazda Protege5 Autostick
I have noticed an increase in fuel milage. Not much but over time it all counts. I do alot of interstae driving and usually cruise around 80 with the sport shifter so my milage is kinda crappy anyway.
 

Dexter

Banned
Contributor
ZapWizard said:
I beleave so.
There are two lever switches:
One turns on the A/C
The other activates the fresh air circuit.
Cool, thanks.

As long as the A/C compressor clicks on, i guess its all good. what else could the actual button do that the switch doesnt?
 
Man, wonderful write up, i wanted to do this but i never really had the time to figure it all out, going to do this tomorrow. I knew i was getting a little bit on the bad side for gas, becuase I always leave it on defrost and rear defrost, and i just drive along not even noticing my GF turned it to 1, or i did. So now this will solve a couple of my problems.Thanks
 

Dimitrios

Contributor
:
2012 CWP MS3
Great how to! I'm definitely going to put this on my long, short list of things to do...

Question: I was wanting to change the potentiometer on the fan speed to a constantly variable one (i.e. like a volume knob) so I can throttle the fan. 1 is good, 2 is a little too loud..some variable point in between would be nice.

Did anyone note if the fan speed pot. is replaceable by anything over the counter (i.e. Radio Shack, etc)?
 

Dexter

Banned
Contributor
Dimitrios, its not a pot. its a rotary switch. i dont think its possible (well..it might be ...with alot of rewiring..) to create variable fan speed. the fan connector has 5 wires - one for each fan speed and a ground. position 0 connects nothing. position one connects wire one and ground, position two connects wire two and ground, etc.
 

Dimitrios

Contributor
:
2012 CWP MS3
Gotcha; I figured it was with the notches, but I've seen pots setup that way too.

I rented a Grand Pricks last week while in Min. and it had a nice, reactive HVAC system. Made me wish my Pro had something similar.
 

Dexter

Banned
Contributor
Grand Pricks (lol)

You've got me thinking now.....what if you just put a pot (well..to be more correct a LM317 (or other) voltage regulator...im sure you would need like 1watt pot or some huge s***) between fan speed 4 and ground...i dont know if the fans would even spin up at 5V or lower though......SO the answer would be to use PWM. Use PWM on fan speed 4. Only bad thing about PWM is sometimes fans/blowers do not like PWM at too low of frequency and they make grinding noises. You've got me thinking though...
 

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