The woes of air-conditioning fault finding. Any ideas

[Daddy Nev]

Hello all,

A lovely day here in Norwich and hopefully it is around most of the UK. With it being 15° and sunny, today we went out for a run in the edge.

However, it was not a great trip. It was getting rather warm so we adjusted the temperature down to 19°. A few minutes later, I adjusted the temperature down to 17 as we weren't getting any cooler. It just did the fan manually and noticed we still weren't getting any cooler.

When we got home I'll pop the bonnet, turned on the Aircon manually and noted that the AC clutch was not turning.I broke out good old FORscan and did a full scan. NO errors and then started the car and repeated. NO errors. I set up the live data screen and included all the AC options in the list. Started the car and started the live data stream. No faults and everything is in the right parameters, just no turning clutch. I've now gone through the fuses and metered them, no blown fuses, swapped the relay over from the horn and tested and that works. I have also turned the clutch by hand and that is free.

So.... I am stumped! There is gas in both sides of the system. I can only think that the clutch assembly solenoid has failed or there is insufficient gas pressure for the system to engage clutch. Now I know that you're supposed to get your AC gas as in R134a topped up every 3 to 5 years, but this being a US vehicle uses R1234YF. I am not sure if the 3-5 year re-gas applies to that or not and I also don't know what the Kpa reading should be when standing. There are also not many Garages that do the newer R1234yf and my trusted local does not. A cheap AC Pro refill bottle is £100 from Halfords and you still need the new larger adapter as well. I dont want to spend £150 on a DIY re-gas when it may be something else. Money is super tight.

Does anyone have any ideas please?

Cheers DN.

[unofix]

1 hour ago, Daddy Nev said:

I can only think that the clutch assembly solenoid has failed or there is insufficient gas pressure for the system to engage clutch

.....and that is most probably the problem. Once the gas pressure falls below a certain limit the AC system will not run the compressor.

Most major service centers have the gas for your vehicle, it is actually now very common. Not that this is a recommendation but even Kwik Fit have it.

Maintenance of the air conditioning system is not a DIY option unless you have all the equipment needed to carry out the evac and recovery of the gas. Then the system has to be put under vacuum for around 20 minutes to check for leaks. If no leaks are discovered then the system will be refilled with the exact correct amount of gas. Remember the gas is hazardous and will blind you if you get it sprayed in the eyes.

[StephenFord]

14 minutes ago, unofix said:

...Not that this is a recommendation but even kwik Fit have it.

I know there are precious few fans of KwikFit on here for a multitude of reasons, but I have used them in the past for an A/C recharge. Basically, if it doesn't work, you get your money back! Try that at your local garage. Go on to their web site to see the full T&Cs...

[rd457]

2 hours ago, Daddy Nev said:

Now I know that you're supposed to get your AC gas as in R134a topped up every 3 to 5 years, but this being a US vehicle uses R1234YF. I am not sure if the 3-5 year re-gas applies to that or not and I also don't know what the Kpa reading should be when standing.

When did you last top up the refrigerant in your fridge? Probably never. When the system is fundamentally the same in a car, why then do you need to occasionally top up a car's system? Because the parts in a car are flexing and bouncing about all of the time and this leads to leaks. Issues with rubber seals on places like the service port valves can also cause leaks. You only need to top up if/when sufficient refrigerant has leaked out to make it necessary or to restore optimal function. This is a universal concept, there are no absolute fixed time frames for any specific refrigerant. This 3-5 year time frame you've picked up somewhere is just some rough guideline someone has come up with based on their experience of automotive leaks. Ignore it. Either just leave it until it stops working or working well enough and then have it fixed, or if you can afford it, have it checked and repaired every so often on whatever schedule works best for you (for which the environment may thank you).

2 hours ago, Daddy Nev said:

I dont want to spend £150 on a DIY re-gas when it may be something else. Money is super tight.

The refrigerant is gone because it has leaked out. A DIY re-gas, besides being extremely hazardous as unofix has pointed out, isn't going to fix the leak(s). You simply cannot fix leaks yourself, if you can even find them, without the necessary equipment to extract any remaining refrigerant (to comply with the law) and to bring the entire system down to a vacuum afterwards before refilling (to get rid of any air that has entered the system). You also have to factor in taking care to ensure that the system contains the correct amount of oil afterwards (yes I mean the A/C system, it requires a small and specific amount of oil to be in it).

Also, please don't describe your financial situation as being "super tight" unless it truly is so. Nobody for whom money truly is "super tight" would even be contemplating blowing £100+ on fixing a luxury like A/C. It's a little offensive, though I'm certain you didn't mean it to be.

2 hours ago, Daddy Nev said:

Does anyone have any ideas please?

When you can afford to, get it to a good garage who will actually fix the leak (which may be as simple as just replacing the service port valves - very cheap) before properly refilling it. It would also be great if they added a little UV leak detection dye to make finding the next leak much easier.

[StephenFord]

24 minutes ago, rd457 said:

Also, please don't describe your financial situation as being "super tight" unless it truly is so. Nobody for whom money truly is "super tight" would even be contemplating blowing £100+ on fixing a luxury like A/C. It's a little offensive, though I'm certain you didn't mean it to be.

LOL, I guess 'supertight' is all relative! Personally, although having a decent 'disposable income' in the past, am now managing on a very tight fixed budget. Driving an 18 year old car is a guideline to how tight I find things! Though she's a great old girl, only ever breaking down once at a roadside with steam bellowing out with a broken heater matrix seal. After filling up with 2 liters of bottled water permanently carried in boot, I still was able to drive her home!

I've been lambasted on this forum for buying 'budget' tires, and cheaper pattern parts. Water off a ducks back, you do what you need to do.

I confess to driving my Focus a couple of years back with broken A/.C. It almost killed me, I hate a car with no A/C and have it permanently on all year round. I've since had the compressor replaced (a £30 used eBay part), and a new condenser (a £90 pattern part). 

If it wasn't for poor folk like me, the rich folk would have no one to buy their cheap parts