Hi, I'm new in this forum..be gentle with me

I have Mazda 3 2.0 L 5 doors, `06.
I live in Israel which has a very hot weahter most of the year.
I noticed the A/C compressor is disengangin when I drive hard and fast - i.e - full throttle, high revs.
Since I am a very aggressive driver and I live in the country side, I find my self driving without A/C for long minutes,
and I can't stand it.
If that's not enough - the hoter is it outside - the more likely the A/C will stop.
I went to the dealer, they did a test-drive with me, with the diagnostics computer connected, they confirmed the A/C
is disconnecting, but it's normal behaviour, since the compuer realises the driver wants max power - it cuts the A/C...
I checked this in another identical car - same problem. but on the 1600cc model - it doesn't happen.
Now I have to find a solution by myself - the dealer can't help me since it's by design and no way to bypass it in the computer
program.
I was thinking to run a bypass wire from the A/C button to the compressor directly. ot via a relay - would this work ?
Did anyone hear of this issue ?
Can you guide me to a solution ?

 

Be careful as you don't want the AC compressor to overheat.

FYI...Max AC is achieved with the system in recirculate mode. (It only needs to cool from whatever your interior temp is rather than having to cool from the high outside temps.) I believe that the AC compressor kicks in via a magnetic clutch. I'm not sure how you would bypass that.

 

thanks, assuming that in normal car (like the 1600cc) the compressor works all the time in hot days, it's shouldn't be
a problem.
I'm aware the recirculate mode is cooler - it's not the issue here - the compressor just turns off.

The main computer controls the compressor with electrical on/off siganl, probably 12v/0v.. so if I find this
wire, disconnect it from the computer and connect it to the A/C button - it should work, shouldn't it ?

 

Sounds logical to me, but I'm a Mechanical Engineer. Can't hurt to try, but if you blow something, it won't be covered under warranty. My thought is that if you run the compressor all the time (100% duty cycle) the compressor will overheat. It may not, but I know they aren't designed to continuously cycle.

I've got the 2.0L in my Mazda3 and don't seem to have the same issue (although we don't see the continuous heat that I'm sure Israel gets.) Although it does get quite humid here and I've been happy with the AC performance of my car thus far.

 

I have a new idea. I noticed that if I run the same up-hill road, once at noon, when it's very hot, and once at night, when it's pretty cool, there is a real difference. at noon - most of the way the compressor shuts down, at night - almost 100% working.
If the computer is designed to shut down the compressor when there is max power demand - it shouldn't be related to external temperature.
I suspect there is a miss-design of some other component - maybe pressure or overheat sensor that shut down the compressor too soon. it happens in 3 different cars I tried (2.0L only, 1600 is fine).

does anybody have the electrical drawings of the AC system of mazda 3 2.0L ? where can I find it ?

 

Another problem with running the AC continuously instead of letting it cycle is risking freezing up the evaporator. If it's a ball of ice then you're not getting any colder.

 

Of course, I'll be aware of this and turn it off manualy when needed...

 

Now that the summer is back again... I have to solve this problem, any ideas ?
Does one of you fits this profile ? :

- own mazda3 2.0L
- drives at hot climate (above 28c let's say)
- drives aggressively

If you do - did you notice the A/C dissconnects for long periods ?

Does anyone have schematic drawings of the A/C system ?

Thanks for any help

 

I meet your criteria (at least in summer), but I haven't had the issues you report.

PM babyhuey, he probably has the diagrams you are looking for....

 

billm at www.mazda3forums.com has developed a modification to the A/C. Basically he wired in a resistor to the thermistor to fool the A/C into going about 5 degrees cooler. He also has a timer to control how long it will do that.... So it stays on longer (trying to make the temperature it thinks it hasn't reached) for 7-10 minutes, and then he dials it back to keep from freezing up the system.

I've purchased another mod from him to get variable intermittant wipers, and it works perfectly. If you ask he may make one to sell to you.