Need help with air conditioning problem

personoid · Post by **personoid** » Tue Dec 21, 2010 8:59 pm

I have a nice little 1990 MX5, well maintained.

It has air conditioning, which has worked well.
Up until today, that is!
Today, when I turn it on, it doesn't cool the air at all, only air at ambient temperature comes out the vents.

The engine revs do drop slightly, as per normal, so I'm guessing it isn't a fuse.

It suddenly stopped working, so I'm guessing it isn't the gas slowly boiling off over the years.

Any idea what the problem might be?

Yesterday was the hottest day of the year, 28 degrees in Auckland. Perhaps that has something to do with it.

Thanks

Personoid

Dez · Post by **Dez** » Tue Dec 21, 2010 9:26 pm

I had a similar problem a couple of years ago in my 4WD. The Tech-sperts
checked it over & found nothing particularly wrong with the units. (Got
my '94
Five checked @ same time) What they did advise however: that on a hot day,
really hot day, to put the air selector to Recirc & the aircon will work that
much quicker & better colder than on Fresh. It will keep on cooling the
cooling
reciculating air to get below cabin ambient temp. On Fresh the aircon will be
getting a continuos supply of hot air from outside therefore the aircon
units 'struggle' with outside air to cool the interior compared to the initial
start-up from the interior on Recirc. Clear as mud?
I've followed that advice ever since and seems to do the business well.
Occasionally I remember to give the cabin a short blast of fresh to change the
air, so to speak.
Remember, YMMV,& it's my fourpence worth.

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personoid · Post by **personoid** » Wed Dec 22, 2010 8:21 am

Thanks Dez,

I tried that, and unfortunately it didn't do the trick!

Also, air conditioning didn't work first this this morning, at about 7:30am!

Perhaps the sensor that measure temperature is broken?

Personoid

Timmo · Post by **Timmo** » Thu Dec 23, 2010 8:45 am

The fact that the revs are dropping mean the pump is working but my guess would be that the refrigerant has leaked out- Easiest way is simply to take it to an Air Con specialist- They will be able to sort out what the issue is fairly quickly.

Coming into summer, a lot of cars loose their aircon due to owners not using it regularly during the winter- lack of use/lubrication means the various seals in the system shrink and the gas leaks out.

Ben.Nakagawa · Post by **Ben.Nakagawa** » Thu Dec 23, 2010 2:41 pm

The old car in this age may still use R12 gas which is legal to release to atmosphere with knowledge of it is R12.
New safer R134 gas system (different bulb and sealer I think) can be retro fitted with same compressor.
However, I suggest contact to specialist and what their opinion they may has R12 gas in stock as some (like me) converted to R134 system.

See this thread:
http://www.mx5forum.co.nz/viewtopic.php?t=9263

It was about 350+GST to convert whole things.

You may be lucky and get fixed in different way, but be prepare.

broomfish · Post by **broomfish** » Fri Dec 24, 2010 7:47 am

i was feeling quite hot in the car the other day when i noticed a couple of levers by the sunvisors so i pulled them and found the whole roof folded down, whoda thought that!

Ben.Nakagawa · Post by **Ben.Nakagawa** » Fri Dec 24, 2010 8:59 am

I was asked by the garage how much more air need when your roof could be down?

Well, Air-con is fantastic to cool you down while sun is cooking from above so the heater while top down at coolish night

Stevo · Post by **Stevo** » Fri Dec 24, 2010 9:22 pm

Ben.Nakagawa wrote:I was asked by the garage how much more air need when your roof could be down?

Well, Air-con is fantastic to cool you down while sun is cooking from above so the heater while top down at coolish night

Agreed. Cheers Stevo