Hi

What with the recent hot weather i have notice that the Air Con on my ST works to start with and then it just stops working, when engine seems to get to normal temp(between about 5-10ish miles into journey).

I have had the System checked and was told it was full of gass, and that the condenser was not working - although it clearly works to a point as works initially when i set off!!

Any ideas, could a thermostat temp sensor cause this?

Al

 

does the air con fan kick in????

 

When start engine up from cold it works then 5 miles or so down the road it just fades away. When i pull over and press the button it sounds like it cuts in and revs drop slightly.

Al

 

Most modern systems cycle on off normally, as they are much more effecient than systems of years ago that sapped loads of power, does it stay cool inside the car that's the point, don't worry whether it is on or not, as in actually running as it will turn on and off as needed.
tabetha

 

After the engine has 'warmed up' the Air con stops being cold and acts as if its the car does not have Air Con on.

AL

 

You say the A/C place said the condenser was faulty so this obviously needs looking at and is probably the problem?

Martin

 

The Guy said the condenser was probably faulty, but this was when it was warm and when the Air Con does not work. The Condenser obviously works as when i am in it when the engine is cold the Air Con works. But when he looked at it as the engine was warm it Air Con was not working. It was from Kwik-Fit who check the gas so not relying totally on his assesment.

Al

 

Could be a valve problem, take it to a air con specialist, would be money well spent.
tabetha

 

I would take to an air con specialist. There is a low pressure switch in the system which stops the A/C from working when the gas is low so perhaps it is this, but normally it would not work at all.

Martin

 

could also be the in-line drier(part of the A/C pipework) choking, will be ok for small amount of time but will eventually slow flow of refrigerant and cause a trip at pressure switch, the condenser fan should run when the compressor comes in although some systems will keep it off on start up until it reaches optimum pressure then cut in, also could be a 2 stage fan, 1st stage could be running 2nd stage not coming in, then trip press switch again, A/C engineer will tell you, kwik fart only good for re-gas, past that it needs better equipment, try and get a guy to do it as a homer,

 

as asked before... is the air con fan kicking in???? the reason i ask is because i had this on a saff years ago, identical symptoms, it is cold as you start up and pull away because the engine and rads are cold. when the engine warms up the heat bleeds onto the aircon rad and the air becomes warmer, the fan should cool it down if it works, mine however was f**Ked and didnt cool the air back down. i replaced the fan and hey presto it was a lot cooler. HTH

 

if the ac fan dont kick in then the the head pressure will rise and the gas cannot change state properly and will not be sprayed through the block valve creating the cooling affect also some compressers have a thermal cut out located on the ac pump and can cause the pump to stop. if the clutch cap on the compresser is to big it will not cut back in .what u need to do is get it on an ac machine and read the pressures high side should be about 200psi if it goes above 280 psi fan should cut in low pressure should read about 50psi if it is pulling a vacum on the low side the block valve has had it if the clutch has cut in and pressure is even pump has had it pressure switches can cause your kind of problem over gasing and under gasing also