[david_geng]

Hi, there,

I got a 54 reg Grand Scenic. The air con pressure is ok. Sometimes the air con can kick in, sometimes not. When it is "not", I mean the air blown out is warm all the time. The air con light is always on. I wonder if it is a sign for any problem? or how can I make it working reliably?

cheers
David

 

[madnoel10]

When you say the air-con pressure is OK - how was it tested or checked.

When the air-con is switched on at idle can you hear engine revs alter o rhear a click from the compressor?

 

[david_geng]

I have a air con top up can with the pressure gauge, and it shows exact at the middle of the green area when I connect it.

When the air con works, the engine revs drops and I can feel the coldness of the low pressure pipe.

 

[madnoel10]

If there is insufficient refrigerant in the system the compressor won't kick in.
As the amount of refrigerant should be measured on weight therefore pressure is not a good guide as to its actual contents.
I am not saying this is your exact problem but this apsect should be considered.
The pressure sensor for the air-con system is usually located around the bottom of the condensor at the front of the radiator and can be subjected to water ingress - it may be worth checking its electrical terminals are clean and sound.