Mist from vents.

[peterm15]

I read a couple of zombie threads that somewhat matched my problem but they all came up as archives and had no solution. So I decided to start a new one. If any of the mods want to merge feel free, but please pm me the new thread name.

This happened a few times last year but just the other day happened again. A mist/fog is coming from the 2 centre vents if the AC is on bust for more then 5 min. I'd like to take a video but my iPhone will not catch it.

There is no smell, no leaks inside the cabin and I know it's moisture as it will actually create a "dew" on my centre console if left long enough. It happens wether on recirculate or not.

The only other symptom is the fan seems to slow down. It still pushes out coldish ( about as cold as my 3 has ever gotten) air but it's like turning the fan down to 2 from 4.

Can anyone elaborate on what's happening and what I (can do to fix this)? If I just need a recharge will the CT kits work or do I need to take it to a mechanic?

Thanks in advance.

[loki]

Similar to the misting inside of an airplane?

[peterm15]

Similar to the misting inside of an airplane?

Can't say I've ever seen that. I've only ever been to NFLD and FLA on an airplane.

[DDUKI]

I had something happened couple days ago. Fogy thing coming out from vent when I had a/c. Not exactly sure what setting of the vent I had but I turned ac off and on it was gone..

[boo-ninja]

I had something happened couple days ago. Fogy thing coming out from vent when I had a/c. Not exactly sure what setting of the vent I had but I turned ac off and on it was gone..
condensation?

[SonicBoy]

I've seen this a few times in all of the 3's I have from 2007 up to my 2012.

What is happening is the air has too much moisture in it and the evaporator is unable to remove the moisture as the air passes. The fan kicking down is attempting to slow the amount of air passing through the evaporator and reduce the fog coming from the vents.

There's nothing really you can do to fix this other than maybe roll down the windows and allow the air to vent out of the car until it cools down somewhat.

[peterm15]

If this was a one time thing or always happened with my car I'd think nothing of it. The fact that it's something new and seems to be happening more often there must be a fix.

The fan kicks down so much that it won't cool the car anymore.the air temp is fine but it's not powerful.

[SonicBoy]

If that's the case then something must be wrong and you may need to take it to a shop or someone that knows more about AC.

[peterm15]

If that's the case then something must be wrong and you may need to take it to a shop or someone that knows more about AC.

That's what I was afraid of. The only problem is I can't replicate the problem.

[Cab0oze]

Mist sounds kinda nice though! Better than the nasty smell that I get when I turn mine on :(

[peterm15]

Lol. I guess your right. Better then a smell

[TheMAN]

if air is slowing down, the evaporator is freezing... known problem on 06-09s.... a TSB was issued and a special resistor jumper wire gets added to the evaporator temp sensor in order to make the compressor cycle off at a higher temperature as well as using the baffled 05 cabin filter to change the air flow characteristics

[peterm15]

if air is slowing down, the evaporator is freezing... known problem on 06-09s.... a TSB was issued and a special resistor jumper wire gets added to the evaporator temp sensor in order to make the compressor cycle off at a higher temperature as well as using the baffled 05 cabin filter to change the air flow characteristics

Thanks I will look for that TSB.

[peterm15]

Found it.
Bulletin number. 07-004/08

Subject:
A/C STOPS COOLING/REDUCED AIRFLOW DURING A LONG DRIVE IN HUMID TEMPERATURES

APPLICABLE MODEL(S)/VINS
2006 - 2008 Mazda3 vehicles (including Mazdaspeed3)

DESCRIPTION

Some customers may report that with the A/C on during an extended drive, the vent air volume decreases and/or the vents start to blow warm air. This could be result of the evaporator freezing, and it is most likely to occur while driving for an extended time at steady highway speeds with the A/C on MAX in high humidity conditions. When the freeze-up occurs, the following symptoms may be present:

^ During freeze-up, the low pressure side pipe will have frost on it, giving the appearance it is frozen.

^ Allowing the evaporator to unfreeze will temporarily address the concern.
NOTE: There are other conditions that can create similar symptoms, which include:

^ A/C cutoff control operation, where the PCM stops energizing the A/C relay when certain conditions are met. This can include the following situations:

- During acceleration (throttle valve opening angle 50% or more). The duration is 5 seconds.

- When ECT (engine coolant temperature) is 113°C (235°F). The system repeatedly turns on and off every 20 seconds until the ECT is less than approximately 110°C (230°F).

- When ECT is 117°C (242°F) or more. The system will remain off until the ECT decreases to less than 114°C (237°F). These conditions signify the engine is running hot and could be on the verge of overheating.


^ Electrical or mechanical concerns that could restrict vent air flow, causing irregular operation of the blower motor, and/or engagement of the A/C compressor.


The cause of the evaporator freeze-up is product variation of the evaporator temperature sensor and uneven airflow across the evaporator. To correct the sensor, a short harness with a built-in resistor will need to be installed in series with evaporator temperature sensor circuit. This cord will correct it by reducing the measured value 1°C (1.8°F). To correct the airflow, a cabin filter with a built-in diffuser will need to be installed in place of the current filter.

Customers having this concern should have their vehicle repaired using the following repair procedure.

REPAIR PROCEDURE

1. Verify customer concern.

2. Record the customer's radio station presets.

3. Disconnect the negative battery for at least one minute.

4. Remove the side wall on the passenger side foot well.

5. Remove the Passenger Juction Box. Refer to MS3 online instructions or Workshop Manual section 09-40 PASSENGER JUNCTION BOX (PJB) REMOVAL/INSTALLATION.

NOTE: PJB module configuration does not need to be performed since the same module will be used.

6. Remove the metal bracket.

7. Disconnect the connector from the evaporator temperature sensor connector.

8. Disconnect the power MOSFET (if equipped with automatic climate control).

9. Remove the evaporator access cover from the A/C unit.

10. Remove the upper and lower air filters from the A/C unit.

11. Install the air filter with diffuser plate.

12. Install the air filter.

NOTE: Make sure the arrows marked on the air filter are facing towards the rear of the vehicle.

13. Install the evaporator access cover to the A/C unit.

14. Install the short harness with resistor to the connector, then connect the evaporator temperature sensor connector to it.

15. Reassemble in the reverse order of removal.

16. Reconnect the negative battery cable.

17. Verify repair.

18. Enter the customer's radio presets and set the clock.


From

http://www.mazdaforum.com/forum/mazda3-26/tsb-mazdas-19889/page4/


Now just to find out if I can purchase that harness and do this myself. It seems pretty straight forward.

[TheMAN]

sure you can:
BP8P-61-J6X Air Filter Set (with diffuser plate) 1
BPY1-61-545 Short Harness (with resistor) 1

[peterm15]

sure you can:
BP8P-61-J6X Air Filter Set (with diffuser plate) 1
BPY1-61-545 Short Harness (with resistor) 1

Thanks again.