I know auto climate control will blow hot until car is warm but mine just blows hot all the time. Windscreen gets hot with all the hot air (so do my feet!).
If I turn the temperature down to cold it flips to blowing freezing cold air (at around the 18 degree mark on the dial).
I’ve removed the glove box and can see the air ducts behind the panel. As I move the temperature knob I can see that the flaps in the ducts flip from one extreme to the other.
The local Mazda dealer doesn’t know what the problem is either and nothing showing on diagnostics monitor.
Anyone seen this before or know where the thermostat hides?
I had a similar problem with my Octavia VRS. It was blowing cold all the time, even when the temp was set at 25 degrees. The only way to get hot air was to set it max and then it was full heat. It turned out to be the sensors that are placed inside the Csr in the footwell area. Once they were replaced it was fine. It may well be the sensors in yours.
Are you sure that it’s not just doing it’s job? On Auto setting, the system will try to get the cabin to the set temperature as quickly as possible. If you’ve set it at say 20 degrees and the temperature is less than that the system will pump out warm air until it’s reached that temperature. If you turn the temperature knob to below the cabin temperature the system will cool the cabin as quickly as possible. The sensor is behind a little grille I the dashboard, from memory to the left of the steering column.
Yeah, I know it’s supposed to blow hot or cold until it reaches the desired temperature but with the fan on auto it just blows hot air at full speed unless I turn it down to 17. Then I get cold air at full speed!
I had a look as you suggest - there is a small grill near the DCS OFF button to the left of the steering. I took a look behind and there are 4 thin wires to a plug on the DCS switch but nothing behind the grill - no sensor, no wires. I looked to see if anything was loose, a hanging loom or wire but couldn’t see anything. Am I looking in the right place?
There’s nothing behind that grill - I can see light coming through when I wriggle my head into the drivers footwell.
It does have climate control as two of the 3 heater controls have AUTO on them and the right hand one is also labelled A/C.
Hmmm any suggestions? Or do I take it back to the Mazda dealer and point out I’m a sensor short?
The on board diagnostics should have shown that up I’d have thought. Someone’s not fitted an Auto AC panel to a non Auto AC car have they? What spec car is it? The pipe isn’t tucked up out of the way somewhere is it?
Run though this, this is what the dealer should have done.
1. Turn the ignition switch to the ON position, then press and hold the A/C switch for 5 seconds or more within 10 seconds.
2. Turn the fan switch to the OFF position.
3. Verify that all the indicator lights of the climate control unit illuminate.
4. Press the recirculate switch or turn the ignition switch off.
5. Shine a 60 W incandescent (a normal bulb with a filament) light from a distance of 10cm vertically to the solar radiation sensor which is the round disc on the drivers side of the top of the dash board. If you don’t do this you’ll get a fault for the solar radiation sensor which you can ignore if you don’t have a light. It’d be nice to know if the solar radiation sensor is working though.
6. Turn the ignition switch to the ON position, then press and hold the A/C switch for 5 seconds or more within 10 seconds.
7. Turn the fan switch to the AUTO position.
8. Turn the mode dial one position at a time (1.auto, 2.open mode heat, 3.open mode bi-level, 4.open mode vent, 5.vent 6.heat) and observe whether the A/C light is on or off in each position.
9. Press the recirculate switch or turn the ignition switch off to finish.
Verify that all the indicator lights of the climate control unit illuminate.
Yes, all lit up
Turn the mode dial one position at a time (1.auto, 2.open mode heat, 3.open mode bi-level, 4.open mode vent, 5.vent 6.heat) and observe whether the A/C light is on or off in each position.
I also have … position 7.bi-feet and screen, 8. Screen only.
OK, the AirCon light was ONLY illuminated when the dial was selecting “Feet only” (position 6 of 8)
At all other selections the AirCon light was out.
I also held a 60W lamp above the solar radiation sensor, above the windscreen outside of the car.
And I had another good look - there is no rubber tube or sensor anywhere near the vent next to the DSC OFF switch.
That VIN shows the car as not having Air Conditioning so it seems either someone’s retro fitted some(?) parts of an AC system to it or just fitted an Auto AC panel.
Does the air con actually work? Does the compressor lock in and the fan run when you switch it on? I’ll let you know what the test results mean ASAP.
No probs, you can click the link at the top to join the Club
When I press the A/C button it lights up but there is no sound of an A/C unit clicking in.
Looks like it’s just a button with a light on it!
OK. I can live without A/C (sound of grown man crying) but full heat/freezing cold is another matter.
Is it easy to get the AC panel out to look behind and will fitting a sensor stabilise the temperature? is there another way? … or is life not that simple?
(I may have to click the link and join. I’ve had my money’s worth already )
Are there any AC components under the bonnet? Would you know what you’re looking for?
The wire probably isn’t there to fit the sensor, it’d probably need the solar radiation sensor as well. I’d look for a used non AC control unit, easy enough to change, it comes out with the audio unit.
Well, I’d look for a compressor but can’t see one.
And I’d look for a recharge point - there are a selection of pipes but all seem to be cooling, steering, brake hydraulic - nothing with what looks like a recharge point.
I pulled the radio and 3 knob heating panel out to take a look.
Interestingly only two screws holding it, no locking bolt in the side and some tape securing the harness had been cut so I’m not the first person to go in there (!)
There’s a single wire harness plugged into the back of the heater control panel. No sign of any pipe.
I think you’re right - it’s not the original panel and there’s no A/C. (sound of grown man crying again)
Time to look around for a non-A/C panel…
Thanks again, I really do appreciate your help :o)
I know it’s no help to you now, but this may help someone else in the future.
The feet/screen & screen position have no function during the test so you can ignore them. If the AC light illuminates it means that system is OK, if it’s not illuminated then there is a fault with that system.
The Auto position is a check of All Sensors
The Open/Vent position is a check for the Ambient Air Temperature Sensor (which is located behind the front bumper)
The Open/Bi-Level position is a check for the Cabin Air Temperature Sensor
The Open/Heat position is a check for the Solar Radiation Sensor
The Vent position is a check for the Evaporator Temperature Sensor
The Heat position is a check for the Air Mix Actuator (which is a module on top of the heater box behind the dashboard)
I seem to be having an issue with my A/C and have run through your diagnostic.
1.auto - Off (auto) 2.open mode heat - On (Face/Waist) 3.open mode bi-level - On (Both) 4.open mode vent - Off (Feet/waist) 5.vent - On (Face Only) 6.heat - On (Feet Only)
I also have two more
Off (Two small triangles) 8. Off (Windscreen)
I couldn’t do the Solar test as finding as 60w bulb is a bit of a challenge
So am I reading this correctly in that everything tested has passed?
Turning on the A/C only has a minimal impact of the idle revs, and after ten mins both the High & Low A/C pipes are both still the ambient temp, not one hot and one cold.
I’m assuming I can’t test anything else myself and need to try a re-gass place?
Having followed Robbie’s diagnostic test I book my car in to the local F1 Autocentre for an AirCon regas. I booked and paid online (just £42 inc VAT) and now the A/C air temperatire us around 11 degrees C.
Can’t fault the service - though the machine does everything - and if they can’t make the temp lower, the don’t charge you anything. And £7 cheaper than the KwikFit offering.
