My ac sucks

[tomwitt]

About a month of 105+ days have me seeing some AC issues. When sitting still, even stopping at redlight cold air drops to warm air. AC seems underpowered all the time for this Texas weather. Anyone else feeling my pain? Suggestions?

My recirculate light is always on.

2010 5 touring

 

[JovaBear]

Recharge your AC.

 

[Silentnoise713]

Looks like you have a 2010. Take it in to get checked. This car's AC is weaker than most other cars i've been in but it is decent. Granted I have 20% tint and liketo park in the shade where possible, perhaps you can take some of these measure. I'm not familiar with Texas heat so can't say for sure.

The recir should help in coolimg.

 

[icspots]

Assuming Mazda did the same thing with the 5 as they did with the 3......... basically the AC doesn't work particularly well, however they 'fixed' the problem by changing the design specs. So while most cars can blow AC in the 28-35 degree range Mazda increased their range up to around 45 or so (I'm trying to remember numbers from reading a thread a few years ago so my numbers probably aren't totally accurate) so that the higher temp would still read 'in spec'.

To address the poor cooling in the 3 Mazda released an air defuser..... basically a plate with holes in it that slid into the air duct where the air filter is on equipped cars to slow the air flow down. Slower air spends more time being cooled so it makes the air cooler by virtue of hindering the air flow.

The only actual modification I've seen which truly addresses and improves upon the problem is an AC mod performed by billm on M3F. What he did was bridged the AC thermistor with a resistor which tricked the thermistor into thinking the AC was blowing ~5 degrees warmer than it actually was. Since it thought it was too warm it cooled the air down more. He ended up wiring a timer onto his modification since making the AC cool harder all the time could cause the evaporator to freeze up thus stopping all cold air flow. The timer would let the mod run for "x" amount of time and then disconnect the resistor from the circuit and let it operate normally. The initial increase in the AC's performance helped cool the car down to the point where normal operation could keep it cool in the car.

I have this mod installed in my 3 with a manual switch to disconnect it (budget didn't include a timer) and it makes a huge difference in cooling. It's probably that the same thing could be performed on the 5.

Some other things you can do to help your AC along:
-use a sun shade when you're parked. The 5 (and 3) have huge black dashes, which become superheated after spending a lot of time in the sun. Anything you can do to help reduce that will decrease heat radiation from the dash.
-tint your windows. You don't have to go limo on the windows to get an effect, however you may want to look into getting higher performance ceramic tints which reject higher percentages of heat. I have a 40% ceramic which rejects 80% of heat vs. the 20% metallized tint that rejected 50% heat that my installer also carried.
-keep your AC on face only when you first turn it on. When you split the air between face and foot some of the air is being diverted to the rear vents. If you keep it on full face for several minutes before switching to face/feet then it helps cool down the dash and keeps more of the cold air on the front seats.
-open your windows when you're first getting into your hot car, and if possible drive a little bit with them open just to help clear some of the very hot air inside.

 

[thaxman]

If you can remember - after you open all the doors and tailgate to evacuate the hot air that has been building up while you left the car parked and unattended - the set the climate control to draw FRESH air in, since it is quite often cooler than the interior air of a parked car - particularly one with a black interior or dark exterior. After a few min, you need to remember to switch it back to recirculate tho, or you are not going to be using the cooler interior air that has displaced the old hot air.
As for it warming up when idling at stoplights, my wife has complained about that too, but I have not experienced it at all. I usually drive the car in the eves, so I don't experience that. I have only experienced the compressor clutch disengege upon medium to hard acceleration to not rob so much power in that setting. But I wonder if it is disengaging when idling at stoplights too. Our compressor was replaced 2 1/2 yrs ago under warrantly, so I doubt we are running low on refrigerant. Could be tho. Never know unless you (or I) check.

 

[Wishmaster]

Your A/C sucks? Hmm that's weird, cause mine really blows... Hahahahha, sorry for the unhelpful post, I just couldn't pass up the opportunity!

 

[flcruising]

To address the poor cooling in the 3 Mazda released an air defuser..... basically a plate with holes in it that slid into the air duct where the air filter is on equipped cars to slow the air flow down. Slower air spends more time being cooled so it makes the air cooler by virtue of hindering the air flow.

The only actual modification I've seen which truly addresses and improves upon the problem is an AC mod performed by billm on M3F. What he did was bridged the AC thermistor with a resistor which tricked the thermistor into thinking the AC was blowing ~5 degrees warmer than it actually was.

That's funny, there's a TSB for this resistor mod for the Mz3, but it's to decrease the perceived temperature because of the evaporator freezing up when traveling long distances. I'm sure it's only a matter of having the resistor in series with the thermistor instead of parallel like your mod. I'll look into the one you spoke about.

OP, I've found that unless you start out driving at highways speeds and get the cabin cooled, then the auto climate control works against you in city traffic because the blower first comes on full blast and never really decreases. If you can get used to turning down the temperature and setting the fan speed manually to about 3 notches, the vents pump out much cooler air than what the auto climate system tries to do. Basically, we've found that the auto climate control only works satisfactorily in the winter and on the highway.

 

[Sounbwoy]

I've found that using the rear air seems to also have an effect on cooling efficiency as well. It really only gets used when my son is with me (I don't have too many passengers). My only issues with A/C are sometimes in the morning, it wants to run in floor/vent mode before switching to vent only, and sometimes there's a significant variance between a degree of temp which in my case is 72 and 73

 

[mpvue]

of all the mazdas I've had, this AC works the best. I use the auto setting all the time; I just put it at 68 degrees and let it do its job. I've never noticed it warming up while sitting still.
btw, 'charging' the AC is NOT the be all/end all answer to AC woes. if it NEEDS a charge, its because it has a LEAK; otherwise, recharging is not a normal maintenance procedure. auto parts stores make us think you can buy a can of refrigerant and fix it like you're putting air in tires, but it doesn't work that way.

 

[flcruising]

I looked into billm's Mz3 timer mod and have concluded that a better approach would probably be to tap into the recirculate mode button. Mainly since a few of us here have had the evaporator freeze up on long trips, specifically because the climate control was bringing in fresh humid air. This would minimize the potential if the mod was only activated with RECIRCULATE on.

 

[90210]

I have a 40% ceramic which rejects 80% of heat vs. the 20% metallized tint that rejected 50% heat that my installer also carried..

Do you have any pictures? I picked up a 2012 5, and tint is the first thing I would like to do. Howeve,r instead of going dark for privacy, heat rejection is the most important factor on this car.

 

[Sounbwoy]

it was 101 here in RTP today..I keep my a/c at 72 and it worked fine. I remembered some of the tips from above (set to fresh air and run on manual then switch to recirc and auto after a bit) and it DID seem to cool down a little faster. It got better as the drive home (highway continued).

 

[Davebert]

I am having a similar problem with my AC which I though it was fixed when the AC clutch was replaced. The AC would work fine until I'm stuck in traffic. I have done some testing and I found it is not the compressor because I put the car in neutral and rev the engine at a steady 1500RPM and it was still blowing warm air. I coasted down a long hill in neutral and the AC work as it should blowing cold air. It looks like the car has to be in motion in order for the AC to work properly.

One last thing I noticed was that the temperature gauge and the needle is at around the 3/4 mark when I was stuck in traffic and once I start moving it when down to the 1/2 mark. I had the AC off at the time and did not tried to turn the AC on when the temp gauge was at the 1/2 mark because I was busy driving. So, it might have something to do with coolant temperature where the car will disable the AC if it thinks the car is overheating. The source of this problem might be a fault in the cooling system causing the AC to stop working. I have already change the thermostat last year when the temp gauge went to the "H" position a couple times when we were stuck in traffic.

 

[Davebert]

AC problem solved, I think.

I think my AC problem has finally been solved. With our recent hot weather the car almost got overheated when we were stuck in traffic. We had to open all the windows and turn the heating on to keep the engine from over heating. The radiator/condenser fan is suppose to turn the fan on when the AC comes on or when the coolant temperature is over 91C. The fan was not turning on. I checked the fuses and relay and they were good. The problem turned out to the be a loose connection at the radiator/condenser fan so it would never turn on. The connectors are right the front of the car, under the duct for the battery. You have to remove that duct to get access to the connector. Hope this will be of some help to someone.

 

[DKaz]

Davebert, good to know.

OP, have you resolved your issues?

Was gonna joke, if your A/C is sucking... turn the fan around, your A/C is supposed to be blowing. (headbang)

 

[MazdaBro]

I've heard the AC is a bit weak in these cars, but you should be feeling war air. Get your AC recharged or take it in to get looked at. I can't imagine driving in 105 heat without it!

 

[Davebert]

It has been almost a week and the AC seems to be working as it should. I have my Maxitrip ODBII reader connected to the car and it can show me the Water Temperature(WT). When the fan was not working the WT when high at 107C. Now, when the car is in motion the WT stays around 89C, it will peak at 93C when I came to a stop after coming off the freeway or I'm stuck in traffic. The radiator fan seems to be doing its job.

The AC now continues to work and blows cold air all the time even when I am stuck in traffic.

 

[flcruising]

The only actual modification I've seen which truly addresses and improves upon the problem is an AC mod performed by billm on M3F. What he did was bridged the AC thermistor with a resistor which tricked the thermistor into thinking the AC was blowing ~5 degrees warmer than it actually was. Since it thought it was too warm it cooled the air down more.

I did this mod with two 100k resistors in parallel today = 50k ohm.

With the 100+* degree weather, we'll see if the wife notices a difference. I just soldered them together and jambed them into the backside of the connector. If they cause evap freezing issues, it's a simple reversal, but we always try and run with recirculate on, so I doubt it'll be with the weather this hot. If I could get to the fresh air diverter motor wiring, I'd just hook it up with a relay to only activate with recirculate, but that will have to wait until the weather gets a little cooler before I rip into the dash.

 

[flcruising]

The billm mod works! The a/c blows so much cooler that one of my daughters actually asked for the rear air to be turned down to LOW. That hasn't happened all summer!

Next step will be to try and wire it to the recirc motor like I mentioned above so it can be left alone year round.



So, for those of you who would like your a/c to work better this summer. Simply take a 1/4 watt 47k (or 2 -100k like me) resistor, fold each leg in half and twist it so the ends become thicker, and insert it into the backside of the evap temp sensor connector. 3 minutes max!

 

[DKaz]

Does it affect how the automatic climate control works though? aka too cold. I don't want to be in an oven but I don't want to be in a fridge either.