arc960

Hi guys:
I have a 2005 Mazda 3 Hatchback and recently I have been having problems with the A/C. I'm driving with my A/C on and suddenly I will feel hot air comming through the vents, I will look at the A/C swith and the green light will be off. I will push it several times and the light will come on and the air will get cold again. I have taken my car to the dealer in 3 opportunities with no luck, they have not been able to find the problem.
Any ideas?

Hyperion

I know the p5 has that problem too, I read on another forum that the plugs that are connected to the switches didnt all get crimped on really tightly and they sometimes wiggle loose. I have that happen and have taken it to the dealer as well and they dont know either. I just deal with it : /
I guess this could be a problem on the 3 too. I will try to find that thread later today.

Hyperion

Heres the link. Its actually for a fix of the p5 controls, but I think it sounds like the same problem, I dont really know if the dealers would do anything about it (covered by warranty or not) hope this gives you some help. http://www.mazdas247.com/forum/showt...hp?t=123678992

arc960

Thank you very much Hyperion for your advice. Weekend project.

Hyperion

just keep in mind thats for a p5 may wait to see if someone with a 3 has it too. dont you still have a warranty?

jrdrake4

I recently had this same problem with my wife's 2005 Mazda 3s sedan 2.3.

Went to the dealer about 3 times they were unable to fix it while it was under warranty. We noticed that when we hit the side of the dash next to the AC controls the unit would come back on. I also hooked up an OBD II Scanner and saw that the request for the AC was going away and noticed that the green light on the AC unit was going off. Now that the car is out of warranty, I went to a junk yard and picked up the whole AC control unit which included the three controls and the circuit board. Put the new (used) unit in and have not had a problem since.

I checked around the junkyards in Phoenix and found the price for that part ranged from about $45 to $120. Not sure what the part is from the dealer.
The whole job took about 90 minutes to do once i decided to replace that part, and hooking up those control cables can be a little challenging.

Hope this helps!

heman2002

Guys use the service manual and do to yourself. here the link


http://cgi.ebay.com/ebaymotors/ws/eB...m=190323252309

orlandoman

jrdrake4: you are right about the rotary blower switch issue causing the AC light to blink on and off but it is not aways the mating terminals on the connector. I have a 2007 Mazda 3 S sedan and found the rotary switch itself has an intermittent contact internal to the switch as well. In my case the back matting connector was not the issue but the grease inside the switch was contaminating the contact for the blower speeds and the ac demand line that should be continuously on from speeds 1 to 4 and off at zero. I took the 3 switch AC control panel out and removed the center switch which is not part of the circuit board. This switch is black in color and can be taken apart by popping the 3 lock tabs. Clean the grease off and use a wire brush to burnish the copper traces and the three raised dimples on the rotating matting part. Clean the copper dust off with compressed air and alcohol. I reassembled the unit without grease, silicon or otherwise and it seems to work flawlessly. I dont know how long it is going to work but if it lasts 3-4 years I will be ok with that. Now another AC problem a lot of people I found has a problem with is the ac unit cycling on and off a lot in hot or mild weather or the unit blows warm air for no apparent reason when the compressor should be kicking on. After making sure the high side pressure switch was working ok and checking the high and low side pressures when the ac was cutting in I figured out the evaporator temperature sensor was bad (open resistance) and fooling the ac control unit into thinking the evaporator was ice cold. The temperature curves for the part has the resistance of about 7,000 ohms at 32F and about 3000 ohms at 68F and 1500 ohms at 95F and 1000 ohms at 122F. On cooler days I found the unit would read the right resistance and when it was hot inside the car or outside it would read open. Now i found that the sensor is buried in the evaporator core and requires taking the whole dash out to get to it at a dealer cost of 500 to 1000 dollars . Since I was not willing to do that I had a simple fix to bypass the whole sensor and fool the ac control unit into thinking the evaporator was 68F inside and keep the compressor on. What i did was disconnect the 2 pin connector that leads to the AC control unit (dont cut this cable) . THen locate the gray jacket wire that goes to the evaporator core though a hold on the right side of the assemby and leads to the 2 pin connector you just removed earlier. cut the cable that leads to the sensor itself and remove and retain the connector that goes to it (long nose pliers to squeeze the hole pop tabs.) Cut the wire about 4 inches from the connector and solder a 2700 ohm 1watt resistor to the wires on the connector end. Leave the cut sensor wire hanging as it doesn't carry power. Use electrical tape to cover the resistor leads and soldered connections. install the connector back into its retaining hole and put the mating connector back in and test the ac to see if the clutch works then and gets cold inside. Now the only issue I found with this is the compressor will not cut off when the evaporator freezes up which hasn't happened here in florida during the hot months, My suggestion is during cooler days when using the AC use the blower on the higher speeds and on recirculate and use the temperature mix **** at the 10 o'clock position to mix some warm air into the cabin to melt the ice on the evaporator. The other down/up side with using this fix is the clutch is aways on (less wear) when running unless the motor revs high or the high side pressure switch cuts it off or the car is almost overheating. My typical vent temps with blower on #4 and 100 degress outside cruising at 2000 RPM ~50mph is about 40-45 deg. Note I know this works with manual control AC, I am not sure it will work with the climate control AC version as other interior sensors are involved for the A/C computer

zxd5298

i have a 06 Mazda 3 s 2.3 and my ac compressor does not always come on unless driving for awhile. the system is charged and holding pressure when it is on it is ice cold.

blendedpdx

I recently had a problem with my 07. The A/C wasn't coming on until I drove for about 10 miles, then it would be spotty. I read another post about the relay so I removed it and re-seated it and so far after trying it a handful of times, the compressor has kicked on each time.

Dedylan

I've been digging for DAYS now trying to find out what in the world is going on with my 2009 Mazda 3s and your issues/solutions are exactly what I was looking for! If possible, I could use some help with locating wires and figuring out where to solder in the resistor! Thank you so much for taking the time to write this up and I think you're going to save my life this summer (Living in Vero Beach).