Technical Question about aircon

[Bogbeast]

I got my 1.8 ELX just over 3 years ago and found once I hit the summer that the aircon wasn't working. I wasn't able to afford doing anything about it until I had my latest service in November and paid £85 for an aircon service including re-gas.

I haven't driven it much since then but in the last few weeks, during the odd bit of decent weather, I've noticed that the aircon doesn't seem to be kicking in. I've got the switches set to "Lo" on the temperature guage, "Auto" on fan speed, blower direction set to face level and the aircon button pushed in. As far as I can tell that should kick in the aircon system but I don't get any cold air.

One thing I noticed is that when the engine is idling and I press in the aircon button there is no change in engine pitch. Given the fact that the compressor should be starting, should I not be able to hear a slight dip in engine revs when it kicks in?

So, before I head off to garage and make a complete fool of myself, is there anything further I can do to test to see if it's something obvious?

Oh, and I've checked all the fuses that I think will remotely be involved in the system.

Cheers

 

[mark85]

sorry can't offer any ideas as i have the same fault as you
posted a while a go if you trace fault could you post it here
and if i do trace it first will post also ..ta mark

 

[Stu DemonD]

So hasn't the aircon been used since November? That is 6 months ago?

It should be used at least once a week, even in winter.

 

[bulldog5046]

So hasn't the aircon been used since November? That is 6 months ago?

It should be used at least once a week, even in winter.

what happens if you dont? i take it it just stops working like with these guys?

 

[T14086]

You should use aircon in winter at start up as it removes moisture from inside the car/screen.Anyway if the compressor isn't cutting in the aircon obviously isn't working...you can test the temperature at the middle air vent on full speed should drop down to 4 to 7 degrees.

 

[b1gduk]

When you press the aircon button , does the clutch on the compressor engage ?

Look at the compressor

If you look on in the middle of the pulley when aircon is on it will be turning around, it will be still if aircon is off.

Also any leaks in the system will allow your gas to escape. Would be better to have an aircon specialist look at it and do a leak test than keep regassing and loosing it shortly after.

 

[T14086]

Alot of aircon compressor clutches spin constantly wether on or off...luckily this (for testing purposes) is a recent development but one to watch for in the future

 

[b1gduk]

Perhaps they do , I am no expert however I have owned two fiats and checked this myself earlier today and I can safely say that on my Marea (and I am guessing that the person posing the problem also shares the same car as this is the Marea Technical section) I can see that when the engine is ticking over and I put aircon on, the insidre of the spinning part of the compressor is turning, when it is off it does not.

I know from my Fiat coupe days that this was an indication of a relay or other electrical related problem but I wont go down that road because it may well be functioning correctly , just loosing coolent.

 

[JoskeJTD]

Sounds like a leak. Some places offer free diagnosis of the aircon. If the coolant drops below a certain level the aircon compressor fail safe kicks in to prevent you damaging the compressor. When you had the regass for your car, did they put a special dye in? This dye can only be seen with a UV light. If they had, get a UV light and shine it around your engine you'll see if there are any leaks. Could be pipes, or aircon radiator, even compressor seal. Shouldn't cost too much if its just a pipe. But obviously the regass will.

 

[T14086]

Perhaps they do , I am no expert however I have owned two fiats and checked this myself earlier today and I can safely say that on my Marea (and I am guessing that the person posing the problem also shares the same car as this is the Marea Technical section) I can see that when the engine is ticking over and I put aircon on, the insidre of the spinning part of the compressor is turning, when it is off it does not.

Yes your right...one to watch out for in the future I mentioned

As for the dye.....yeah that stuff is great when going out to nightclub...you stand out like a beacon!

 

[mark85]

further to my last post phoned the garage they said if my aircon light comes on it most likely needs re gassed so off to the garage this week to have it done quoted me £70 + vat does that seem reasonable ? will let you know if its freezing in glasgow

 

[T14086]

Lets hope so cause forecast is hot all week/weekend