The AC has little if any extra cooling effect over and above the normal fan and temp dial in my fabia. This was diagnosed as a holed condenser, which I had replaced and regased for best part of £500 (ouch!) However a month later AC back to old problem. Can anyone tell me what the temp should be at the dash vents, so I can go back and argue my case. Anyone any idea of likely causes?

Thanks in advance

The AC has little if any extra cooling effect over and above the normal fan and temp dial in my fabia. This was diagnosed as a holed condenser, which I had replaced and regased for best part of £500 (ouch!) However a month later AC back to old problem. Can anyone tell me what the temp should be at the dash vents, so I can go back and argue my case. Anyone any idea of likely causes?

Thanks in advance

My temp at the aircon unit was 4 degrees c if that helps.

Ouch indeed!

Shifty is right, you should be looking at 4-7 degrees at face vents. When you go back and they check it, you need to find out whether the system pressures have dropped right off which will indicate another leak in the system. They really need to do a "sniff" check (if they have the equipment of course) which will pin point non visible leaks from joints etc. If pressures are ok, there could be a simple electrical fault though these are unusual.

A dye check is usually better than a sniffer.

Need to read off the fault codes, this will tell you if anything electrical is stopping it working.

I'd agree that a dye trace is the first thing to look for but should that not show anything up, a sniff test will find the smallest of leaks where no dye or fluid would ever be present. We use it all the time and is very accurate at pin pointing leaks when no dye trace or fluid loss is visible.

The trouble is when time is money (and probably your money) the adding of dye will always win hands down first time round, but then you have traces of dye left around the car, so next time round it becomes a bit of a problem. On large systems when someone needs to take stewardship ie accountability of what weight of gas is loaded into the system, what weight has been recovered and what weight of gas is taken on site, and what weight of gas has been lost, the only way to deal with these leaks is OFN with a trace of fridge gas and a sniffer. The car A/C industry is lucky it is not held so tightly to account as it can always be claimed that the owner had a problem and lost the gas, unfortunately this can lead to what "might" have happened to you, ie garage found main source of leak, replaced that assembly, whacked it on their machine which pulled an "industry standard vacuum" in the allowed time - so system is fit for recharging. I took my 2000MY Passat into VW for replacement of a couple of seals (oil was being forced out at bulkhead connection) "you can't see leaks" - so system only got the correct empty>vac>reload and it still leaks oil and will need recharged next year - "good job" "give us your money we are certified experts" ?!?