Aircon- delayed activation

[bigwinn]

Anyone experienced this at all?

Aircon takes approx 5 miles of driving to kick in at the start of the day
After that if I stop the car it comes back on quicker but still delayed

Ice cold- regassed and pressure excellent no leaks

Think its a pressure switch or something?

Also checked and swapped fuses and relays

Cheers

Stuart

 

[j3nks79]

Could be pressure switch. Fairly cheap and easy to replace.
Is the rad fan kicking it as soon as you turn AC on?

 

[bigwinn]

Nope

 

[enuff_zed]

So next time, start the car, switch the the AC on, then pop the bonnet and tap the switch.
Maybe it is just sticking a bit?

 

[j3nks79]

Nope

IIRC as soon as you switch AC on the rad fan should activate.
If it doesn’t the AC doesn’t work

 

[enuff_zed]

Nope

IIRC as soon as you switch AC on the rad fan should activate.
If it doesn’t the AC doesn’t work

It's all linked to the signal from the pressure switch though isn't it?

 

[bigwinn]

Is the pressure switch ‘in’ the system- like to replace it I’ll need to de gas?

 

[j3nks79]

Nope

IIRC as soon as you switch AC on the rad fan should activate.
If it doesn’t the AC doesn’t work

It's all linked to the signal from the pressure switch though isn't it?

If the system detects low pressure then yes it won’t switch on. But I had a problem recently with no AC working. I vacuum tested the system and re gassed it and still didn’t work.
I didn’t have any rad fans kicking in. Changed the rad pack and all started working.

 

[j3nks79]

You would also get a code for low pressure if you scan with with INPA etc

 

[enuff_zed]

Is the pressure switch ‘in’ the system- like to replace it I’ll need to de gas?

There should be a non-return valve under the pressure switch so you should be ok.
Only one I ever swapped was with an empty system, but the bloke who regassed it said there was one.

[ref]j3nks79[/ref], has a couple of good points though. So before you get to my point of clouting the switch, stick INPA on it before you switch it on and see if the low pressure warning stays on, then goes off after a few minutes.

 

[j3nks79]

Is the pressure switch ‘in’ the system- like to replace it I’ll need to de gas?

Replaceable without losing any gas. Sits on one of the ac pipes.

 

[bigwinn]

Thanks gents

Sounds like a valve issue

 

[Pondrew]

There should be a non-return valve under the pressure switch so you should be ok.

Refrigeration circuits do not generally have non-return valves in them. There may be a schrader valve under the switch, which I suppose could be classed as a non-return valve. But you wouldn't know until you unscrewed the switch and released quite a bit of refrigerant (which is potentially dangerous and illegal).

Are you all sure the E85/6 runs the cooling fan permanently with the a/c on? The E89 definitely doesn't. It is controlled by a signal from the HP switch and cycles on high pressure only.

 

[j3nks79]

It’s has a schrader valve on AC pipe.

 

[enuff_zed]

There should be a non-return valve under the pressure switch so you should be ok.

Refrigeration circuits do not generally have non-return valves in them. There may be a schrader valve under the switch, which I suppose could be classed as a non-return valve. But you wouldn't know until you unscrewed the switch and released quite a bit of refrigerant (which is potentially dangerous and illegal).

Are you all sure the E85/6 runs the cooling fan permanently with the a/c on? The E89 definitely doesn't. It is controlled by a signal from the HP switch and cycles on high pressure only.

You say Schrader, I say NRV.
Fulfils the same function for the OPs purpose.