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

[ZapWizard]

Disabling automatic A/C - Defrost


2003 Mazda Protégé


http://www.zapwizard.com/Car/air/dash.jpg






<HR>



Most modern cars are getting more and more fool-proof.

One thing that car makers now use is "Automatic A/C and Defrost"
What this does, is if you turn the knob on your car to defrost, then the car pulls in fresh air, and turns on the A/C automatically.
Taking in fresh air, and de-humidifying it, the windows defrost faster; but it is not always needed or even wanted.





<HR>http://www.zapwizard.com/Car/air/Auto-AC.jpg

When using the defrost vent modes, you can't use recycled air.
And your A/C is also turned on, robbing horsepower.
(Even though the A/C light does not turn on)




<HR>


http://www.zapwizard.com/Car/air/Disabled.jpg

Once completed this modification allows you to take back that control, you set the fresh air, and A/C settings no matter what vents you use.



<HR>The tools needed are:


Philips screwdriver
Small flathead screwdriver.
Needle nose, or similar pliers
Exacto-knife



<HR>Thanks to MaxxMazda for the original help. http://www.protegeclub.com/forum/showthread.php?threadid=25430 (http://www.protegeclub.com/forum/showthread.php?threadid=25430)





<HR>http://www.zapwizard.com/Car/air/glovebox.jpg

First remove the glove box.
Open it, push in the sides at the top, gently lower it, the pull towards the driver side, and down to release.





<HR>http://www.zapwizard.com/Car/air/Glovebox-Off.jpg

Look inside and towards the drivers seat.




<HR>http://www.zapwizard.com/Car/air/cable1.jpg

Locate the temperature control cable and disconnect it.

Gently push the tab in and pull the cable off the white control arm.

The push down on the black metal holder, and pull the cable surround out.



<HR>http://www.zapwizard.com/Car/air/Drivers-side.jpg


Next move the drivers side, and locate the vent control cable.



<HR>http://www.zapwizard.com/Car/air/cable2.jpg

Repeat the same steps to disconnect the vent control cable.





<HR>http://www.zapwizard.com/Car/air/Pulling-Panel.jpg

Next you need to pull the center panel out.

This is done by pushing the vents down, and pulling with both hands.




<HR>http://www.zapwizard.com/Car/air/Connectors.jpg

With the center panel hanging out, disconnect the hazard signal button,
and the two connectors at the rear of the A/C control assembly.



<HR>http://www.zapwizard.com/Car/air/assembly.jpg


You can now remove the entire center panel.

Be careful to note how the control cables come out, so that you can put back in the correct way.

Once removed unscrew the A/C control assembly from the front panel.



<HR>http://www.zapwizard.com/Car/air/Faceplate.jpg


With the panel removed, carefully pull the three control knobs off.



<HR>

/Edit- removing the A/C and Defrost buttons is not needed



<HR>


http://www.zapwizard.com/Car/air/Faceplate-Knobs.jpg


You should now have no knobs on the front



<HR>http://www.zapwizard.com/Car/air/Faceplate-removed.jpg


Pull the front faceplate off by pulling up on the two holding tabs on each side.

You will see a circuit board behind the faceplate, don't pull on it.

We don't need it. But you could make changes to the LEDs or the colored caps on the backlights here.



<HR>http://www.zapwizard.com/Car/air/cable.jpg


We need to get under the other black plastic cover.

But first you need to remove the temperature control cable.

Do this by spreading the center tabs on the white holder, while pulling on the black cable surround.

If have found this step easiest by spreading the tabs with needle nose pliers.

Do not try to pry the cable out, or pull up in any way!

http://www.zapwizard.com/Car/air/Cable-Pull.jpg



<HR>http://www.zapwizard.com/Car/air/cable-up.jpg


Once the black surround is out you can tilt the cable up, and out of the control arm.



<HR>http://www.zapwizard.com/Car/air/Circuit-Cover.jpg


You can then unscrew the circuit cover and remove it.

There are two push tabs towards the front holding it in place.




<HR>

Thanks to TZH for these larger images.
http://www.zapwizard.com/Car/air/CircuitBoard-3[1].jpg

With this circuit board exposed you can see one of the micro-switches at the right.

The other is on the other side of the circuit board.

You do not need to remove these switches, but simply cut their connections.

On the circuit board you will see two thin traces near the white holder.

One has only a short connection on this side of the circuit board,

the other you can see traveling to one of the micro-switches.

<HR>http://www.zapwizard.com/Car/air/CircuitBoard-4[1].jpg

Using an exacto-knife cut into the circuit board, and through the traces.

This is only a two-sided circuit board, so you can cut pretty deep, as long as you don't cut through to the other side.

<HR>

http://www.zapwizard.com/Car/air/CircuitBoard-5[1].jpg

It is best to make two cuts through the traces, about 1mm apart from each other, then use the exacto-knife to remove the copper between the two cuts.

<HR>http://www.zapwizard.com/Car/air/CircuitBoard-6[1].jpg

This will disconnect the micro-switches from the rest of the circuit, and disable the automatic A/C and defrost.

If you want to restore this functionality, you can solder a jumper wire between the solder points of each trace to restore their function.





<HR>http://www.zapwizard.com/Car/air/Disabled.jpg






Once the cuts are made you are finished, and can start to put things back together in a reverse order.

Again make sure to route the control cables carefully so they do not get snagged or loose.

You can now have full control over your A/C, Defrost and Vents.

Remember, when you actually do need to defrost your windows, turn on the A/C and take in fresh air.

[Poseur]

Very well-written, thankyou. I've always thought it was kinda cool that they idiot-proofed it all for ppl, but ultimately being a control freak gets the best of you. and not everyone need the world padded for them.

[servoeyes]

miggity-moved! Good job, BTW!

[CTpro5]

Very nice write-up,and pics. How long did this Mod took? I want to do this so bad.But i'm afraid i will mess things up. was it easy??

[ZapWizard]

It took about 30 minutes.

The hardest part is removing the black plastic surrounds from the holder, and re-routing the stiff cables when putting things back together.

The only part that you could break something easily, is removing the A/C and Defrost button caps. If you do break the plastic tabs, I guess you could glue the caps back on somehow.
(Simple hot glue would allow for easy removal again later)

I actualy did the removal twice today while working on a moonroof always on mod, that I will post later tommorow.

I will do it again when I change out the LEDs, as I want a 100% deep red dash.

I tried to photograph every step, so it should just be a matter of following the guide.

[thumpr]

that's very cool - my sweetie likes to have her feet warm without air blowing on her face - the automatic a/c makes that impractical - is it possible that one of the traces to cut is about the floor vents, and one about the windshield vents? nothing is ever that simple right.

[CTpro5]

I DID IT!!!!!(headbang) I can't believe it myself! and i didn't break anything too.Thanks zap for your wonderful guide. it was a piece a cake!! Thanks a lot!!!!!!!!!!

[Matthew]

you make the best how-tos i have ever seen, congrats on another nice one.

[webster]

Great write-up and reminds me of how much I miss the HVAC in my old E30 BMW.. 3 sliders, one each to operate the defrost vents, dash vents, and floor vents respectively. You could have all three on if you wanted. Then a knob for fan speed, a button for AC, and a button to recirculate the air. Ahhhh total control of the system.

[1Canuck2]

I have a Canadian P5, I swear I can have my window vents on with no AC, but that's going by long lost memories of summer. I'll test this tomorrow.

[fraay]

I have a Canadian P5 and AC turns on automatically with defrost.. same as the US models..

Great write up.. I did this mod last year and have loved it.. I find it incredibly insulting that Mazda trusts me to DRIVE the car, but not handle the "complexities" of their vent system..

Saved lots on gas.. and eliminated all the "fog" problems I was having.. do it! :)

[tzh]

I did it last weekend, the process is pretty easy. Thanks ZapWizard.
Here I have couple of detail pictures.
This is what you will see after opened the black cover. There are the 2 traces.

http://www.wam.umd.edu/~tzhang/Mod/CircuitBoard-3.jpg
__________________________________________________ _______________

They are flat copper lines.

http://www.wam.umd.edu/~tzhang/Mod/CircuitBoard-4.jpg
__________________________________________________ _______________

http://www.wam.umd.edu/~tzhang/Mod/CircuitBoard-5.jpg
__________________________________________________ ______________

Make sure you get rid off all the copper between the gap.

http://www.wam.umd.edu/~tzhang/Mod/CircuitBoard-6.jpg

[ZapWizard]

Thanks for those excelent images tzh.

Do you mind if I download, host, and integrate them into the guide?
(With thanks to you of course)

[tzh]

Go ahead... Let me know if you need the original picz (1600x1200) (yes)

[xfimpg]

I have a Canadian P5 and AC turns on automatically with defrost.. same as the US models..

Great write up.. I did this mod last year and have loved it.. I find it incredibly insulting that Mazda trusts me to DRIVE the car, but not handle the "complexities" of their vent system..

Saved lots on gas.. and eliminated all the "fog" problems I was having.. do it! :)

Hey Fraay

How much did you calculate or estimate that you saved on gas?

Mike

[xfimpg]

Thanks to everyone who contributed to this solution!
I just finished mine and am looking forward to the results.

Mike

[willy65000]

Verry nice. Now if you could just tell me how to do that on My Mazda 3.

[chuyler1]

Sorry to ressurect this but I wanted this done from the day I got my P5. I like to run the heat through the defrost-floor in the winter time because it keeps the dry air from blowing in my face (and making my eyes dry out). However, I also like to get good gas milage which won't happen if I'm running the A/C all winter long.

Excellent post! This should be sticky if it isn't already.

[eting_pro5]

Woah woah woah....mega serious question.

The ventilation system is always moving air through it, even when it's off. Additionally, although the blower is turned to 0, the temperature dial still has a noticable effect on the air coming out.

Does this mean if I leave the controls on defrost and the blower to 0, is my AC still on??? If so, I think Mazda owes me a few grand in gas money....I've never gotten good gas mileage, but I always drive with the vent control on defrost.

[Bumble G]

Woah woah woah....mega serious question.

The ventilation system is always moving air through it, even when it's off. Additionally, although the blower is turned to 0, the temperature dial still has a noticable effect on the air coming out.

Does this mean if I leave the controls on defrost and the blower to 0, is my AC still on??? If so, I think Mazda owes me a few grand in gas money....I've never gotten good gas mileage, but I always drive with the vent control on defrost.
No your A/C is not on when the switch is at 0.

The temp dial makes a difference because it's hooked up to a manual "door" that alows engine cooland to either come into the heater core or not. The air flowing in from outside always passes over the heater core. when you turn the dial to hot, hot coolant runs into the heater core, the outside air passes over the hot core and voila hot air with setting still at 0.

[Blown]

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]

^ 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]

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]

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]

nevermind, ifigured out my mistake.... the solder points for the led were touching... (hand)

[2K3 MSP]

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]

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]

As long as it works, that's all I need. I just hate using my A/C when defogging the windshield.

[Dexter]

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]

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.

[Brian MP5T]

Great Job!

[loccusst]

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]

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?

[loccusst]

Light up green???...JK

[Dexter]

Haha yeah, thats what im thinking...

[GHOSTWHISPER]

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]

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]

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]

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]

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 shit) 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...

[ZapWizard]

Yes, you can change the fan speed settings.

The fan speed control is a five-way switch.
Off-1-2-3-4

It is wired to three resistors that are connected directly to the blower motor.

4 is straight battery to blower to ground. As you turn the speed DOWN (Towards 1) it adds another resitor to the series.

The three resistors I assume are power resistors.
I don't know what wattage, but they should be located somewhere behind the glovebox.

In theory you could replace the five-way switch with one with more positions, like a 6 or 8 way.
It still needs to handle 100% of the power from the blower motor, so you need fo find out how many watts the blower motor uses.
You would then add more resistors to the series to get more speed options.

Another option as above is to use a PWM controller.
This would allow for very precise control of fan speed from zero to ~100%.
You again need to know how many watts (Or Amps) the blower motor uses, and find a PWM circuit or chip that can handle that much power.
http://www.digikey.com/scripts/DkSearch/dksus.dll?Criteria?Ref=124615&Site=US&Cat=31523794

[Dexter]

Yeah i looked that up last night because it was stuck on my brain.

i measured 10A on fan speed 3. i couldnt measure more as my multimeter can only do 10A, but im assuming ~15A on fan speed 4 or 180W!

i was going to look into PWM but i dont think it would be good for the electrical system. no data backing that up, just a feeling. lol

[ZapWizard]

PWM won't hurt the electrical system, if the power rails have some caps close to the PWM controller.

My guess is also 15 to 20 amps. I am thinking about trying to locate the motor or resistors to be sure. The fuse it runs off of is 40amps though.

But lets try to reverse engineer it:

Looking at the service manual it lists the resistace of each resistor:
---.18---.36---1.96---

Total resistance at switch:
1: 2.50 ohms
2: 0.54 ohms
3: 0.18 ohms
4: ~0.01-ohms

It also says the voltages at each position:
-This is across the resistors.
Off: +12volts
1: 0.12 volts
2: 0.65 volts
3: 0.60 volts
4: 0.30 volts

Therefore:
1: +12volts--motor---2.50ohms---GND
2: +12volts--motor---0.54ohms---GND
3: +12volts--motor---0.18ohms---GND
4: +12volts--motor---0.01ohms---GND

1: Rv= 0.12v Mv= 11.88v A=0.048 amps
2: Rv= 0.65v Mv= 11.35v A=1.2 amps
3: Rv= 0.60v Mv= 11.40v A=3.33 amps
4: Rv= 0.30v Mv= 11.70v A=30 amps

We can now figure out the resistor watts.
1: 0.06 Watts
2: 0.78 watts
3: 2 watts
4: 9 watts
That means they should be 10 or 20 watt resistors.

Did I do some math wrong somewhere it seems to be very low wattages?
Logic to me seems like the resistors should be absorbing more watts when slowing the motor down.
These numbers are all from the service manual, actualy measuring the thing would be more accurate.

In order to finish completly we need the wattage of the blower motor.

(Do you guys have any idea how much time you guys make me put into these things?)

[Dexter]

heh nice work zap.

oh i checked out my other question, the one about the difference between the user A/C switch and the internal switch in this mod. I go to the ECU and checked the A/C relay wire (pin 96 iirc) and it behaves the same if i push the A/C button in, or manually press the internal switch.

[viVid]

Excellent instructions, as always. Did this in about 40 mins. in the dark (well, I had a flashlight!). Thanks!

[Brian MP5T]

Question. My control has two microswitched directly conected to the Air Flow Direction Control. Disconection that should also prevent this from hapeneing...

[ZapWizard]

Question. My control has two microswitched directly conected to the Air Flow Direction Control. Disconection that should also prevent this from hapeneing...

http://www.zapwizard.com/Car/air/CircuitBoard-3%5B1%5D.jpg

If you follow the guide your are disabling both switches.
(The AC switch, and Airflow Switch)

[Brian MP5T]

No what i meant to say was why not just break off the little metal flap on the microswitch rather than cutting the connections...

[ZapWizard]

No what i meant to say was why not just break off the little metal flap on the microswitch rather than cutting the connections...

Oh, well if you ever wanted to restore this feature, for example selling the car . Or transfering the car to say, Mom or the wife, who doesn't want to mess with the manual settings.

It's much easier to just apply solder to bridge the connection, rather then try to replace the whole switch.

[Brian MP5T]

The metal lever just comes out and in as you need it. With it not in place, the rotating cam never gets to contact the switch. You how to is stellar, just another way to do it is all I was suggesting...

[dsr70]

There's another reason for the A/C to come on with defrost, other than automakers thinking we're stupid or dehumidifying the air.

In cold climes, where the A/C may not be run for 6-9 months a year, lack of compressor use is a problem. The linking was designed to give the compressor exercise. This goes way back with domestics. With newer compressors and better seals and oils, perhaps the exercise isn't needed. But the design is a holdover I'm sure, probably in the interest of reducing warranty work.

That said, we on this board are clearly not average owners, and can be trusted to run the A/C once a month to lube the compressor.

Doug

[Brian MP5T]

Bump The Heat Wave

[chuyler1]

I rarely use my A/C or Defrost. Last week when I turned it on after it being off for about 2-3 weeks it kept turning on and off on the highway. I was going about 70 and when I looked down the A/C light would flicker off then come back on a few seconds later. After about 25-30 minutes it stayed on. I hope there is nothing wrong. I know it would be one of those things where the Technicians cannot duplicate it until after my warranty is up.

[Dimitrios]

I rarely use my A/C or Defrost. Last week when I turned it on after it being off for about 2-3 weeks it kept turning on and off on the highway. I was going about 70 and when I looked down the A/C light would flicker off then come back on a few seconds later. After about 25-30 minutes it stayed on. I hope there is nothing wrong. I know it would be one of those things where the Technicians cannot duplicate it until after my warranty is up.

Bump; are you still getting this issue?

[wildo]

i just completed this mod. sooooo very easy!

times:
10mins to get unit out (could do much quicker now that i understand the black clips)
10mins to get to and cut the circuit board traces
15mins to install red LED's (see link- change HVAC illumination colors link)
10mins to reassemble

45mins for a killer FREE (if you have 4 led's laying around) mod! thanks you so much for this how to!
change HVAC illumination colors (http://www.msprotege.com/forum/showthread.php?t=58027)

[DarKrID3r]

Hey guys, i have a problem. When my car is hot, i have hot air coming out from anywhere i select, BUT AS SOON AS I CHOOSE DEFROST FRONT WINDOW, the air is COLD COLD COLD.... if i put it back on like head only, its still cold, i need to put the fan back to zero and put it back to 1-2-3 or 4 then i can expect hot air again.

WTF? ??

[wildo]

my only thought is maybe you forgot to plug in one of the two harnesses? sorry i can't help more... well- wait, i just thought up something else-
can you turn the two dials (temp adjust and heater position adjust) all the way in both directions? it might be possible that when you pushed the black part of the cables back into the clips, that they were not in the right positions. i turned mine so that the metal rod comming out of the black sheath was as close in (read- the opposite of extended all the way out) as possible. once it is as close in as it goes, then hook the wire loop, and then push the full cable into the black clips. this will insure everything is as it should be... hope this is clear and that it helps

[DarKrID3r]

i fixed it , there was just a clip on the heat rod that was not in place.

thanks

[Buck]

does anyone know where I can get some replacement bulbs for the Hvac in blue? I can't find any at the parts stores.

[Buck]

also, my rear defrost button stays lit at all times while the ac button doesn't light at all. What could be the problem?

[kyle's protege5]

does anyone know where I can get some replacement bulbs for the Hvac in blue? I can't find any at the parts stores.
They are LED's and there is a thread that shows you how to replace them, there's a link a few posts earlier.

*edit*here's the link
http://www.msprotege.com/forum/showthread.php?t=58027

[Buck]

Well the bulbs that actually light up the numbers and such aren't leds only the ones that light up the buttons are.

[kyle's protege5]

unless i read wrong, in that guys thread, he said he replaced his green led's with red ones so that the numbers and such lit up red too. I've never had mine apart just seen his write up.

[Buck]

ya the ones for the buttons are LEDs but the two for the back lighting are incandescent. I got looked at like I was stupid at the electronics store cuz I assumed they were LEDs :)

[SNike05]

I wanted to do this mod for a while but never got around to it. I was changing the radio so I did this. When I put everything back my temperature knob is very hard now and it won't go to full hot. I checked the cable it seems clear and i'm pretty sure its in the same place but the knob is very hard anyone have any advice?

[Buck]

ya this happened to me. take off the cable, take it out of the little clip (behind the glove compartment area). now make sure the cable is pulled all the way out to its full potential (knob all the way to hot) then push the little plastic arm it connects to all the way over, after this put the cable back on the switch and clip it into the little clip that holds it in place. What happend is when u clipped the cable back into place, the housing was too close to the switch so when u turn the nob to hot the switch is reaching its fully open point before the cable reaches its full extension point, This is keeping the knob from going all the way to hot but the switch is actually fully engaged. This is causing the cable to bind up. The same exact thing happened to me but its an easy fix.

[SNike05]

Awesome thanks Buck I'll try it out. I was hoping someone fell into a similar problem.

[egavasleinad]

Awesome, I am doing this over the weekend!

[Buck]

Awesome thanks Buck I'll try it out. I was hoping someone fell into a similar problem.


did u get that problem with the knob figured out?

[SNike05]

Yep got it fixed basically when I was pushing the hvac in the cable did not go through a clear path. Instead it went through some other wires in a cramped area which was preventing it to flex and move like its suppose resulting in the knob being hard.

So for the ones that will do this make sure the cables of the hvac are sent through the same path that they were removed from. Otherwise the knobs may get harder to function.

[07MZ5SA]

Just tried this mod on my MZ5 manual HVAC.

There are two micro switches: One for A/C and another for REC off.

Instead of cutting traces I removed switches' rockers and trimmed pins.

Total time is about two hours.

[P5inder]

Will this keep the A/C compressor from turning on randomly?

[07MZ5SA]

Compressor will not engage at all unless A/C button is pressed.

[P5inder]

I'm pretty sure the compressor turns on randomly as I can feel the extra drag on the engine while driving...

Even the lights dim while at speed...

I remember it was the same on my 2000 Neon and I disliked it so much that...stupidly, I replaced the accessory belt with a shorter one when I purchased my UDP... (headbang) which, by the way I regretted when I got married and my wife and I went to Utah/Arizona/California and Mexico on our Honeymoon. Not too hot, just too much nagging(chair)

When I tried to use the

[SNike05]

If you have properly removed the copper on the board there is no way the compressor can function without power. I did this a year ago and have never had a problem and the compressor will not go on unless I turn it on.

[07MZ5SA]

Neon's HVAC can be modified?

[wrkngmanByTor]

just did this mod today, so proud of myself! I love this "how-to" section - I've already done the "keyless entry/ ignition on" mod. The hardest part of this one is definitely in the "putting back together" part, rerouting the cables. Also, removing the cable sheaths from the retainers. I don't have a spreader tool, so a small pair of needlenose pliers will do, although not perfectly. The problem is, if I were to go through this procedure again, lets say for replacing bulbs, I think the pliers would eventually wreck the plastic retainers. So, moral of the story, if you don't have the right tool for the job, maybe plan on doing these two procedures at once. Thanks Zap for the excellent write up!

[e-dub]

I just finished doing this, and it worked great! I looked at the online manual, and they made the removal of the center console seem much harder. Just pulling on the vents was much easier!


... Also, removing the cable sheaths from the retainers. I don't have a spreader tool, so a small pair of needlenose pliers will do, although not perfectly....

I tried the needlenose pliers, but mine just weren't small enough, so I went inside and found a pair of scissors similar to these:
http://www.icrc.org/emergency-items/Volume2/04X/XSIN/339XSINMEDI030614/339XSINMEDI030614_files/image002.jpg

They fit perfectly, and the clip opened really easily without any damage at all.

Thanks for the howto ZapWizard!! :D (if you are still around...)

[Wishmaster]

Just wondering... can anyone else confirm this... I'm quite sure the compressor kicks in when it's in the feet only position. Try sitting with your doors open and flick the switch between all settings and I'm pretty sure it comes on in feet only mode as well as the other two. So, my question is does this mod fix this also??

[Stormtrooper77]

Just wondering... can anyone else confirm this... I'm quite sure the compressor kicks in when it's in the feet only position. Try sitting with your doors open and flick the switch between all settings and I'm pretty sure it comes on in feet only mode as well as the other two. So, my question is does this mod fix this also??

This mod will give you FULL control of your A/C. It comes on only when you want it to no matter what position. The only time it will not come on is if the outside temperature is less than zero.

[cybrjoe]

thanks, i did that and now i will have all hp power with defrost on. :)

[ZapWizard]

Thanks for the howto ZapWizard!! :D (if you are still around...)

Sorry folks, I bought a PT Cruiser...slower but more cargo room for me.

[RABID_MP5]

This is a GREAT mod. The only thing I'd add is it's a perfect time to replace the 2 light bulbs (incandescent, not the LEDs) just under the orange plastic sheet in front. Just 2 screws hold the sheet on.

[DreMazdaProtege]

Anybody knows how much it costs to put in a AC system on?

I bought a 2003 Mazda Protege LX 5 months ago and when I bought it I never got to see inside the car because at first I went to the dealership to buy a different car but they sold it so my only option was to buy this 2003 mazda Protege LX and now that the weather is so hot I notice there's no AC on my car, it's stupid because older Mazda Protege's got AC and I been looking online and all the Mazda Protege's has AC.

[jrsmith]

It worked absolutely perfectly. Thanks ZapWizard!

Now it would be great to have a guide like this for a Mazda 3, my next car...

[shadowncs]

Great how-to, first steps helped me in tuning the air direction knob which was not going to defrost at all.I think in spring I might go all the way & do this complete mod, for now days are too short uh...

Anyway a piece of advice when putting all back together - pay special attention to how you position the wire plastic skin inside the metal clips on the side of the heater unit - that's where you tune the knobs position. The manual helped me by providing good instructions - check out section 7-40-11 at http://www.floptical.net/mazda/service_web/07-40.PDF

[Khemraj]

ok so not to beat a dead horse or resurrect the undead buuuuuut... my heat is cranked up and i get cool air...not A/C cold but cool air...will this fix the issue...the car is warmed up...

[blynd_spy]

ok so not to beat a dead horse or resurrect the undead buuuuuut... my heat is cranked up and i get cool air...not A/C cold but cool air...will this fix the issue...the car is warmed up...

sounds more like you have a cable in the back loose and its not opening the vent for the heat. this mod just makes it so you can run in defrost modes without the A/C coming on.

i would check the cable on the right side of the control unit. remove the glovebox and you will see the components for the heat vent. there is a loop on the end of the cable attached to a moving plastic piece. several inches down from the cable there is a clip holding the cable sheath in place. check this clip and see if it moving when you turn the heat dial...

[Khemraj]

hey that worked but what i first noticed was that when i turned the dial it moved the wire, but still blew cold air so i took my finger and pushed it further until i heard a slight click and EUREKA!!! HEAT!!!! Then i moved it back and cold air came back on. So it seems like that when i move it to cold and then back to heat, it doesn't go all the way. Seems like the wire is loose, so can that be tightened and how do i do that? follow the steps from the first post in this thread?

[blynd_spy]

which way is it not going all the way? wire retracting or extracting from the sheath?

if it not retracting all the way back you can trim the sheath or see if there is a kink in he wire stopping it from retracting all the way.

if its not extracting all the way try disconnecting the loop on the wire and move the plastic piece it was attached to all the way up or down and move the dial all teh way left or right, in relation to the wire..

im guessing its option 2 if the wire seems loose however..

note: unless you have removed the A/C unit and taken off the cables then the problem should only be the wire placement on the plastic moving piece. just so you dont remove the unit for no reason..

[Khemraj]

well i guess looking at it, i'd say the wire is not being pulled all the way to the left...i see the exposed wire, the sheath is about less than half an inch away from the white plastic thing

[blynd_spy]

half an inch doesnt seem like enough clearance, but hard to say without looking at it personally.

try undoing the clip, turn the temp dial all the way to cold so the wire is as far out as it can go and the plastic moving piece all the way up. reattach the clip and wire loop and see if you can turn the temp dial all the way hot.

[Khemraj]

it seems like the white plastic is loose cuz it went back to semi cool becuz the white plastic moved back to the right...so i took my finger and pushed it back and it went back to heat...i'll have to look at it this weekend if it's not raining

[larson701]

The procedure for disabling the auto-AC feature works well. A person who has not done much work on cars would need to be cautious. There are many plastic bits involved and too much force will snap those bits. It's an old thread, but a goody.

Thanks!

[Partyman10195]

Just did this to my 03 P5 and it was extremely easy! Took me about 45 minutes once I quit worrying about breaking things haha

[shadowncs]

Finally did mine too, together with fixing the AC flicker on fan pos 2.
One step I'd add is reading the manual on fine tuning the cables - there's clear guidance there and it's worth the extra time!


check out section 7-40-11 at http://www.floptical.net/mazda/service_web/07-40.PDF

Quoting myself feels weird LOL