How to test aircon components?

[UrS4Eben]

Hi all,
Its getting hotter now and I'd like to see if I can get my aircon to work on my '92 S4.
It has the R12 AC system.
I recently replaced the Ambient temperature sensor in the bumper with a 45p thermistor from maplin which fixed the display showing minus temperatures all the time and enabled the ac icon to come on on the klima.

But.... while the ac icon comes on there is no cooling.... there is also no noticable "kick in" when I switch it on(altough I've never had the ac working in the s4)

So... How do I test that the aircon compressor is actually working as its hidden right at the bottom?

Is there a kind of step-by-step guide to test the different components?

PS there is no error codes for hvac on the vag-com

Thanks in advance for the help

Eben

[Skull]

If you have the automatic AC, press and hold in the internal air recirculation and press the up vent arrow, and release both. on the left display will show 01, then press the internal air recirculation button, and write down all the numbers it will show.

[UrS4Eben]

VAG-Com gave no errors.......same as doing it manually on the Klima display...

[Skull]

very strange. do the fans turn on when u press the ac button?

maybe there is no gas, and some AC genius bridged some sensors so there are no fault codes?

[Tomquattro]

Just pulled my codes on a 96 urs6 and it states 00.0

Does that mean no faults found ?

[UrS4Eben]

I'm not sure... would it give you an error code if the compressor clutch is not engaging?

[Jas11n]

If there is no gas in the system, the clutch won't engage on the compressor, BTDT.
However, mines the manual aircon system on an S2, so not sure if this is any different to the climate system on yours.

Jas..

[UrS4Eben]

Thanks for the input.... It would give a low pressure error with no gas... maybe i should take it to a specialist..... any suggestions for these around north west london?

[Skull]

Just pulled my codes on a 96 urs6 and it states 00.0

Does that mean no faults found ?

yes, you AC is clean.

[Skull]

If there is no gas in the system, the clutch won't engage on the compressor, BTDT.
However, mines the manual aircon system on an S2, so not sure if this is any different to the climate system on yours.

Jas..

that is true, but if the sensors are bridged, the clutch will engage, and the AC will report no errors. this way, if your pipes are not filled with gas (and oil!) the compressor will be f***d.

UrS4EBEN: what you are telling us, no fault codes and no cold air coming out of the vents is impossible unless the AC ecu has been tricked (sensors bridged-short circued, whatever)

[cuz-gs]

Aircon

Hi

I went to this place who gave my RS2 aircon the once over, £20 cash for a clean bill of health. My brother in law took his Porsche 944 S2 there as well. Give him a call.

Mirage Air
Unit 9c, Atlas Village, Oxgate Lane, London, NW2 7HJ
Tel: 020 8450 2997

Cheers

Simon

[UrS4Eben]

Thanks for all the info and that contact guys. Much appreciated.