AC problem solving

[moizeau]

Hello, I've got a C4 vts that doesn't spin the compressor. I've had a search through the posts on here but can't find a step by step guide to solving the problem. The previous owner said he'd had a quote of 1000€, but couldn't remember what the garage diagnosed. (Citroen dealership). I also don't know if they're clued up or not having never used them so the quote may be accurate or could be complete cobblers. Could someone point me towards a 'what to check, how to check and in what order' guide please?
Thanks

[EDC5]

The compressor not running is the symptom for most A/C problems unfortunately. There's not much you can check as a DIY unless you have a set of A/C gauges.

A few reasons why the A/C wont work are:

Refrigerant leaked out,
Faulty pressure sensor,
Fuse blown,
Faulty compressor clutch.

I'm not sure if any of those would give an error code to help track them down if you got the car on lexia?

[GiveMeABreak]

The most common cause is low or no refrigerant in the system. The AC compressor is disengaged deliberately to save damage when there is insufficient gas and oil in the circuit.

First option is to get it tested where they will inject a dye with a recharge and then try to locate any leaks. If nothing, you have your AC recharged. If it is leaking or stops again in a few days, they should be able to detect the leak from the dye.

The Condenser radiator is a prime candidate from stone chip damage, or a hose split. If the system is full, then you need to investigate fuses, fan switches and other electrical possibilities before suspecting the Compressor.

I had to have a condenser and the AC compressor replaced on mine last year.

[moizeau]

Right then, first job is to get it recharged with a dye? Then see if it works. I'm sure if it does it won't be for long because the previous owner, a friend, would have done that. Then investigate the leaks or electrics? Is there a way to fool the compressor into spinning up to see if that's at fault? I was also wondering if a genuine condenser change with Citroen's hourly rate would be about the 1000€ quoted? To have quoted that it must be that something needs replacing? Thanks for all the knowledgeable replies, not just this post, but all the others that I am inundating you all with.
Pete

[GiveMeABreak]

If you go to wherever you have your AC topped up or serviced and ask them if they can recharge it and add a dye - then you'll be able to detect whether there is a leak and proceed from there. At the moment, with the absence of a fault from a diagnostic in the AC system, and without the compressor running, it will be hard to determine. You can't get the compressor to engage AFAIK when it is low on gas.

A previous quote for that much sounds like a compressor to me - they are not cheap - but to help you further I need a VIN. I can look to see how much the Condenser / AC compressor is for you to get an idea.

Filling it with gas is not the expensive part. When I had my leak done by Citroen - it took them 4 attempts (!) to locate the leak and finally found it at the top of the condenser.

[moizeau]

Thanks Marc, the vin is VF7**************[VIN obfuscated, can be read by forum staff]

[GiveMeABreak]

£803 inc VAT in the U.K. at 20% for a typical brand new compressor. There are exchange ones available that will be a lot less. There are quite a few variants of compressor, so if it does come down to needing a new one, I suggest you write down the info on the label from your existing one. There are about 10 or so under your VIN so always best to match it with the one coming off.

Only one condenser type, part 6455GK and that is £251.98 inclusive in the U.K. SomInfefinitely think that the previous quote would of been for. New compressor and filling of the system and labour.

[Michel]

See if you can find an independent mobile AC repair man. My recent Renault - the previous owner was quoted £880 to fix the AC..local expert came out, looked at it. £247 inc a new condensor and seals, all fitted in about an hour on my drive.

[moizeau]

Cheers chaps, I'll try and find a local guru. May be interesting here in 'Cowsville'. If it turns out to be the compressor it looks like a guaranteed 2nd hand part or cheaper still, the windows! If nothing else it will give my an reason to learn a bit about the system..
Nice jacket BTW Michel, when I picked up the 407 the other week I noticed how many bike related sign posts there are in Staffordshire and Shropshire. I've still got 'My other car's a bike' in the back window of the Landy.

[Peter.N.]

I have just re enlivened mine with a can of refrigerant and a gauge and connector from ebay, £50 or less although its better to buy the bigger rechargeable cylinder, but be warned the threads are different!

I did mine last year and it has worked fine but not quite so cold this year so topped it up and now its really cold. The new refrigerant also contains oil and leak sealant. It comes with full instructions and is quite easy to use and the gauge will tell you if there is any gas in the system, if not there will be a fairly fast leak somewhere so its no worth wasting the gas.

Peter

[moizeau]

Thanks Peter, did you buy adapters for the threads? Have you got a link to the item / seller please? Does the refrigerant come with a dye as well as the oil and leak sealant?
Cheers

[GiveMeABreak]

Ez chill or STP. Just gave google as there are kits with and without the gauge, and generally have £10 refundable deposit on return of the empty gas cylinder (EU LAW)

https://www.amazon.co.uk/Conditioning-r ... B004XZPANK

That's the one I have now, I previously bought a disposable can and now have a spare gauge as it doesn't fit that one!

If the system is good it should read a high pressure when you connect the hose and drop when you start the engine. That gauge is I think only marked with colours, I filled mine until it was half way up the green, at least I think it was green, a bit colour blind, it tells you in the instructions anyway.

Peter

[xantia_v6]

I have also seen these kits in the french parts retailers (Feu Verte, Norauto etc).

But... If your car has already been diagnosed with a leak, then the system would have been left empty (EU law again), and a refill pack will not work on an empty system, a it needs to be evacuated first.
Alternately, you car may have nothing wrong with the refrigeration system and been diagnosed with an electronic or engine fault, in which case a top-up can won't help either.

[GiveMeABreak]

Yes and you will find that generally the compressor needs to be running when the to up is done IIRC - so if the compressor is not running due to low / discharged gas then it will be difficult to top it up. I think they suggest putting a little gas in to try and get the compressor running - but this will be a non-starter if the compressor is kaput, or there is another cause.

I'm assuming that as the previous owner had it diagnosed with a quote of that magnitude, then it is highly likely the compressor is shot. An A/C specialist though shuld be able to test and confirm it first for you.

[wurlycorner]

And if you don't get the system vacuumed down first, you don't know if it is leak free and it it might also have moisture still in it - which is bad news!
So, best to avoid the can refills and get it checked by a specialist, or even a fast fit re-charge place.