Lack of Air-Con

RichG · Post by **RichG** » 26 Dec 2004, 23:39

This may have been covered before however a search for "Air Con Faults" yields 32 pages!
Coming back from sledging today with my family I decided to use the air-con to de-mist the windows. When I pressed the switch it lit up but nothing else happened. The idle sped did not rise, the fans did not come on and the compressor clutch did not appear to engage. As it took ages to de-mist the windows it appears that I have a problem. The air con did work about a month ago so I am at a loss. As nothing works I am hoping that it is a simple faulty connection. Does anybody have a wiring diagram for air-con as the Haynes BOL does not?
Thanks
Richard

alexx · Post by **alexx** » 27 Dec 2004, 00:31

I presume outside temperature wasn't below 4-5 deg. C like here ?

tomsheppard · Post by **tomsheppard** » 27 Dec 2004, 00:45

Alexx has it. The system is designed to work down to 4 degrees. Below that, it won't.
How this squares with the "run it once a month" instruction, I couldn't begin to fathom,(having only two feet) but Supposing that you don't keep the car in a centrally heated garage, you'll just have to A: wait for spring.
B: drive to Spain (Much preferred option!)
C: blame Bernie of this parish for the nuclear winter which is entirely his fault.

RichG · Post by **RichG** » 27 Dec 2004, 01:50

Well you learn something new everyday! We had driven to Buxton in the Peak District to find a decent amount of snow so it was fairly cold, but above freezing.
Is this "Gaelic Charm" that the air-con will not work below 4 Deg C or do all cars have the same problems?
I will try it again later in the week. Thanks for the quick response
Richard

alan s · Post by **alan s** » 27 Dec 2004, 02:20

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by RichG

Is this "Gaelic Charm" that the air-con will not work below 4 Deg C or do all cars have the same problems?
I will try it again later in the week. Thanks for the quick response
Richard
<hr height="1" noshade id="quote"></blockquote id="quote">
Just the nature of the beast; if it operated below this it would frost up the evaporator coil and wouldn't work anyway and also leave it possible for passengers to suffer from hypothermia I suppose.[:0][:p]
I have suggested before and whilst I haven't done this myself, I can see no reason why it wouldn't work.
Turn the heaters to heat for a few minutes and then flick across to cold. The increase in cab temp should then be enough to trigger the sensor and this associated with the body heat inside the car theoretically should be almost enough to keep it operating.
Where I am we have just the opposite problems; usually compressors blowing up from being overloaded with heat.....and pleeeeeeeeez don't tell me how lucky I am. We don't consider 40+ degree days coupled to 30 degree nights the most comfortable of living conditions.
Alan S

bernie · Post by **bernie** » 27 Dec 2004, 03:00

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by tomsheppard

C: blame Bernie of this parish for the nuclear winter which is entirely his fault.
<hr height="1" noshade id="quote"></blockquote id="quote">
It was cold in the workhouse this christmas[xx(][xx(]

bernie · Post by **bernie** » 27 Dec 2004, 03:02

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by RichG

Is this "Gaelic Charm" that the air-con will not work below 4 Deg C or do all cars have the same problems?
<hr height="1" noshade id="quote"></blockquote id="quote">
Mine don't work when its cold enough to freeze a monkey's[:D]

Post by **martyhopkirk** » 27 Dec 2004, 03:21

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by alans
[brTurn the heaters to heat for a few minutes and then flick across to cold. The increase in cab temp should then be enough to trigger the sensor and this associated with the body heat inside the car theoretically should be almost enough to keep it operating.
Alan S<hr height="1" noshade id="quote"></blockquote id="quote">
Does it not pick up from the external Temp sensor?

alan s · Post by **alan s** » 27 Dec 2004, 03:39

I don't know the exact system that works on these but in all practicality I can't see any reason it should.
I have seen commercial building systems that work on a "differential" of 15 degrees fahrenheit between inside and outside temps but for automotive I fail to see why they would even consider it given the number of bodies as a proportion of overall volume and as body heat is considered the greatest load when engineering an air/con system in a domestic or commercial system, I couldn't imagine why they would want or need to allow for any outside temps in these.
The thermometer on the dash is based on outside temperature and as I often notice, it can be showing around 40 degrees externally but be around say 22 internally with the compressor cutting in & out so obviously, external infkuences only come into playonce they become equal to the internal which makes me feel my theory would work.
Alan S
PS. I do hope all that doesn't sound too roundaboutish as I'm still coming to grips with still being alive after last night!![B)][}:)][}:)][:p]

alexx · Post by **alexx** » 27 Dec 2004, 12:14

<blockquote id="quote">quote:<hr height="1" noshade id="quote">
Does it not pick up from the external Temp sensor?
<hr height="1" noshade id="quote"></blockquote id="quote">
No, it has a separate temp. sensor

RichG · Post by **RichG** » 30 Dec 2004, 01:13

Just to let you know that now the weather has warmed up a bit my air-con is working again. Thanks to all who replied and stopped me investigating a non-existing fault.
Richard

alan s · Post by **alan s** » 30 Dec 2004, 04:53

Richard,
Just out of curiosity, did you ever try the turn to hot then to cold just to see if that did make it operate as I suspected it would?
If not, could someone give it a try sometime just out of curiosity.
Alan S

RichG · Post by **RichG** » 31 Dec 2004, 02:38

Alan,
I didn't have chance to try your theory as we had a thaw before I used the car again. If I remember I will see if I can try it out next time it gets cold.
Richard

alan s · Post by **alan s** » 31 Dec 2004, 02:53

The way the weather is here at night at present I might be able to check it for myself[:D][8D]
It's amazing, prior to the big quake up north, it was so blazingly hot we could hardly breathe and were living in air/con almost 24/7. I've heard it said before that extremes of heat are a forerunner to a quake and right on cue we've since gone from night temps of mid to late 20s to mid to low teens; ahh so that's what it feels like to be able to sleep without air/con???
Alan S[8D]