Air-con's on the blink...again. Starts off working well, but as the day heats up, air-con decides to drop out. Particularly noticeable when the car is parked in the sun for a while - air-con decides it's all too much.

Had it in the shop a while ago, they checked gas, checked for leaks, replaced the reciever/dryer thingo, and a few other things. Worked well for a couple of weeks, then started playing up again - exactly the same problem. Took it back in, this time they said it was the radiator fan on the blink, causing excess pressure and cutting out the condenser....So I replaced the fan, and all worked perfect. Until last week.
Back to the same problem again....

It's heating up here in FNQ, and I have a newborn a 2yr old to keep cool while travelling over the chrissie break.

Any ideas before I take the car back to the shop?

It would be an idea to plug it in to a scan tool instead of guessing but a few ideas

The TX valve my be jamming, these are the conditions that this could happen. Is a PITA ot get out unless you ahve a TL or TW

Could be the temp sensor in the aircon box as well, may be going open circuit when the car heats up inside.

Doubt a fan would cause it as the fan is not running when the engine is switched off.

Also, when you hit the aircon button, does your radiator cooling fan come on but you get no cold air or is the system just dead. If the fan is coming on, check for power at the air con pump, may also be an issue with the clutch in the pump

Is a PITA ot get out unless you ahve a TL or TW
Sorry mate, I don't understand this bit? (mine's a TF)

He means its a..

Pain
In
The
Ass

to get out unless its a TL/TW

So saying you have a TF means its a "PITA" to get out!

SuFz :ninja:

O, I C......So I suppose, given mine's a TF, that the labour costs would be more if it turns out the TX valve is the culprit?

Also, did a little testing today - found a shady park (normally there are none by the time I get to work), and went for a drive at lunchtime.
A/C was C.O.L.D. the whole time, so it appears that whenever the car is parked in the sun for a while, the A/C shits itself...

Car is booked in tomorrow, am getting them to check out the above-mentioned things

Does the aircon button light flash when this happens? I had that happen to me the other day, when it was raining hardcore and lots of water on the road. I assumed that the belt may have been slipping or something where the aircon is connected to, hence why it was flashing and no cold air came out (although the fan was still working as I could feel air blowing)

I waited a minute, turned the aircon off, then on again, and it was working fine again.

Does the aircon button light flash when this happens? I had that happen to me the other day, when it was raining hardcore and lots of water on the road. I assumed that the belt may have been slipping or something where the aircon is connected to, hence why it was flashing and no cold air came out (although the fan was still working as I could feel air blowing)

I waited a minute, turned the aircon off, then on again, and it was working fine again.

Normally when the light flashes it requires a Re-Gas and Service.

SuFz :ninja:

We moved from Townsville 4 years ago so I know how you feel especially with young kids. I had similar problems during summer on a Jag and a VS Commodore where the car would take ages to even begin to pump cold air and by this time the refrigerant was so hot it tripped the high pressure switch resulting in no cold air till the pressure dropped...and then cold for a little time then off. I found on both these cars that if I parked in the shade there was no problem or if I used a windscreen sunshade that completely covered the dashboard it would work much better. I have seen extreme cases where they have installed water sprays to cool the condenser but like I say, that is in extreme circumstances.
The relay for the compressor clutch can also fail when hot if the points in the relay are burnt. Aircons are second only to auto transmissions in $$$$ to repair.

Yep, hearing you there....

Just got the car back - turns out it could be either the tx valve, or the evaporator, or both. Won't know 'till they pull the dash apart - at which point I think it'd be wise to replace both.

Got quoted over $500 for parts + labour, figured the car isn't worth that much, so I just have to find a way of mitigating the issue - either by parking in the shade where possible, or covering the dash with towels when in the sun (sunshade alone doesn't seem to help).

Further ideas? Dashmat?

I've got a dashmat but really don't think that helps, but I find the sunshade really good - mine is larger than the windscreen so no light gets through. A light coloured towel on the dash should reflect the heat....also leave all the windows down 13mm (make sure nothing of value is in sight)....paint the roof white....when air is not working have a clean nappy bucket with lid in the front filled with cold water and half a dozen face clothes sitting in the water...when kids appear hot/stressed just wring out a wet face cloth and give it the child and it provides instant cooling and something to suck on and they don't get sticky as well. (sorry if I'm rambling)
When we moved to Townsville in the early 70's virtually no cars had airconditioning and we just drove with the windows down - we had a 3y.o and a newborn at that stage and didn't know any better (!). I must admit there were no safety capsules or seats which seem to prevent airflow around young kids and no one even had seatbelts except in those luxury foreign cars. However that sure doesn't solve your problem.
Good Luck.

one trick for a sticky tx valve is to rev the engine to approx 3000rpm and turn the a/c on and off so that the compressor is on for 2 seconds and off for 5.... try that for say 10 cycles and it may just loosen it up
this has worked for me on many an occasion where the customers tx has seized from the a/c either not being used or not working for long durations... of course if it dont work then its gonna be need a tx

another tip is to remove your fan speed resistor/transistor and look for a build up of leaves/fur/dust in the evap box as this can hold moisture which restricts air flow thru the evap and causes it to ice up which in turn causes the a/c to lose efficiency..... if it is then give it a blow out with compressed air (and vacuum your car out lol )