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Flashing AC Light

39K views 14 replies 11 participants last post by  Johnny Ringo  
#1 ·
Here's a new one for you all out there. This morning I had some frost on the inside of the windscreen and turned on the air conditioning. The green L.E.D. on the AC button started slowing flashing/blinking (your choice). The outside temperature was about 11 degress Farenheit, in case that had something to do with it. I tried it a little later and the light stayed on -- just like it has every other time I've used the AC over the past nearly three years. Nothing in the owner's manual (of course...) and I couldn't find any threads here. Any ideas? BTW, the car just went out of warranty...
 
#2 ·
I am taking my car in for warranty service (appointment is in two weeks) because of an electrical fault with the same flashing light symptom. My problem is that when I am driving, and the car must be in motion for the fault to occur, if I turn the windshield wipers to full or the "just once" option when you push down on the stalk, the fan for the heater/ac cuts out completely and the button lights on the console start to flash like you've described.

At first I thought it was a loose connection somewhere until I figured out the wiper connection. I don'e know what the deal is yet, but when I get it back from service I will post and let you know the diagnosis. I'd be interested to hear any opinions from Mini2 folks, though. I hate going into the dealer blind.

Thanks.
 
#3 ·
Wiper Connection?

Thanks for the reply to the thread. You know, I had used the wipers at around the same time, but the blower motor didn't seem to change at all. I also didn't sense that the AC compressor turned on when I pressed the button, but then it was so cold that it was hard to think of anything else...
 
#4 ·
My suggestion would be to try to repeat the fault and then start turning things off and on, listening for things cutting out, etc. It's possible the cold could affect it, I had an old truck with a deactivated alarm that would go off randomly in cold and rain, but it's worth checking out. Like I said, mine is all good when stationary, the problem only occurs while driving. I noticed the light on the air recirculation indicator first, then when I found the commonality of the wipers I came to the conclusion that it must be a short somewhere as opposed to a loose connection. It would be interesting if you are having the same problem. Maybe the same guy wired our cars!
 
#6 ·
yellowminijim said:
Here's a new one for you all out there. This morning I had some frost on the inside of the windscreen and turned on the air conditioning. The green L.E.D. on the AC button started slowing flashing/blinking (your choice). The outside temperature was about 11 degress Farenheit, in case that had something to do with it. I tried it a little later and the light stayed on -- just like it has every other time I've used the AC over the past nearly three years. Nothing in the owner's manual (of course...) and I couldn't find any threads here. Any ideas? BTW, the car just went out of warranty...
That's a very clever peice of A.I. circuitry. the car is actually trying to get your attention. Its trying to tell you "you've got to be joking!!!! it 11degrees F. I'M cold, you nutter. turn the heater on. what about me. nobody ever thinks of me do they....." MINI'a are like that. they have feelings. and they can go on a bit. they are british you know ;) :D

In all seriousness are you sure its not actually programmed to flash when the a/c can't work perhaps due to extreme outside conditions. It may actually be a warning to tell you to turn the a/c off, or just to lett you know that it isn't working at the moment. Perhaps it would be worth a call to BMW technical.
 
#7 ·
The only time I have seen my A/C light flash is when the fuse was blown for the A/C and power steering fans. The engine was actually starting to overheat, but hadn't quite registered on the gauge yet. And when it was flashing, I wasn't getting any cold air at all.

As to wanting to use the A/C in the dead of winter, there is a good reason to use it. Not only does the A/C cool down the air, it also dries it out. It also doesn't hurt to run your A/C at least once a month just to keep the system cycling a bit. So you are not nuts for using the A/C in winter. But maybe you are nuts for wanting to use it when it is 11f out.
 
#8 ·
A.c

Flashing aircon light is indication of low aircon gas pressure and thus it flashes to indicate that the system needs re-gassing.
If it's flashing all the time, every time, then it does need looking at. Aircon compressors used on MINI cannot operate 'dry' and thus a de-gassed aircon system is potentially damaging to the compressor if it's switched on.

If the flashing is a one off, this was probably a false alarm triggered most likely by cold conditions causing gas contraction and therefore a low pressure reading.

If it's a 'now and then flashing' then the system could probably do with a recharge to top up the pressure as it's obviously bordering underpressure.
 
#10 ·
Not Really Crazy

I know.... It does sound crazy, but the windshield/windscreen was fairly frosted over on the inside and I was trying to use the AC to dry the air. BTW, it seems to have been a one off, as it no longer seems to flash. Thanks to all of you for the suggestions! I've found the mini2.com forums and the minimania.com class ic Mini forums both to be wonderful communities. It's in the teens again this evening, so I think I'll go out and turn on the AC for fun!
 
#11 ·
I don't think that the aircon will actually work at all if the temperature is below freezing or only just above. You can turn on the light but the compressor won't run.

To dry the air, the system has to cool the air first, and the water condenses out, and runs out of the bottom of the car. Then the heater can heat the dry air up if needed. The first thing the outside air comes to is the cooler, not the heater.

If the temperature of the cooler drops to freezing, the aircon compressor turns off. If not, ice would form in the cooler and block the air flow.

If the outside air is at freezing or below, it will make the evaporator so cold that the aircon won't operate. There would be little advantage, as air that cold cannot contain much water vapour so it can't be dried much more anyhow.

I have seen an aircon system refuse to operate in cold weather. It was the drop in pressure because of the cold, combined with a faulty presure switch.