I finally turned on the aircon rather than taking the top down and got warm air.
The panel code test gave a '23'
Refrigerant pressure switch malfunction or refrigerant pressure low
Knowing my luck the refrigerant will have leaked out through a duff compressor seal but can anyone please suggest a logical series of tests to try to narrow things down for this particular fault code? JTIS isn't helpful.

 

Best way to detect leaks through out the A/C system is thru the use of dye in the refrigerant .

Happy Motoring...

 

I don't have a UV lamp unfortunately.
It's basically a question of is it safe to jumper out the pressure switch to see if the compressor kicks in if the real fault is low refrigerant pressure.

 

Yes....for a short time. However, another way to check that is simply to add a bottle of refrigerant. That should make the pressure rise. And if you are going to add a bottle of refrigerant, you might as well add a bottle of refrigerant with dye (as they are the same price as refrigerant without dye). And if you are doing that, you should spend about $10 at amazon or wherever for a UV light.
Every time I've had an AC issue on any car it has always been a leak. As a side result of the leak, you get low pressure, which prevents the compressor from running and hurting itself. Incidentally, you an also buy a vacuum pump on amazon for about $100 (to suck all the air out / evacuate the system).
When you do jumper it, once you hear the AC clutch engage then you know the problem and should then un-jumper it. By jumping it now, you can get your answer immediately without having to buy anything.

 

Working on a/c without good knowledge and tools is a crapshoot in possibly seriously hurting yourself and/or causing even more problems. Definitely not a place I recommend a novice to poke around. As far as I'm concerned, making refrigerants available to the general public should be illegal. I've seen good techs get into trouble, over the years and it upsets me whenever I hear of someone that doesn't understand the risks forge ahead, armed only with some coaching from friends and internet pals.

 

Time for a stupid question...

How does one access climate control trouble codes for our cars?

 

Hi, to read codes - You hold down the AUTO and RECIRCULATE buttons at same time and turn on ignition, then push the auto button again and the fault codes will cycle on the display. If you have a "0" code that means no codes.

To clear the codes - at the same time push REAR DEFROST and the "ARROW TO FACE " button together.
I would make note of first codes and then clear all codes and then drive for a day or two and repeat to see if same or different codes come up.
There could be codes from along time ago that were not cleared. .

More info on hyper link.

https://www.jaguarforums.com/forum/a...rror-codes-pdf

 

Beav

My nearest 'expert' aircon place (and by 'expert' I mean Speedy, the French equivalent of Kwik-S**t) is 110 km away so I really do need to sort out if it's the switch or if the refrigerant's gone to play with the Ozone Layer.
As a real expert can you give me some helpful advice?
Also I found this diagram for the switch connector. Can anyone confirm these pinouts for the XK series please?
I'm a bit puzzled by advice in another thread to jumper out the 20 Bar contacts.
According to the MSDS R134a has a vapour pressure of 3.5 Bar at 5°C and 5.7 at 20° so, with the system at rest, the pressure switch should be seeing this sort of level which should close the 2-30 bar contacts to tell the ECM that it's safe to engage the compressor.
Maybe I'm missing something.

 

Why not go about it the easy way? Apply power and gound to the compressor clutch for a couple minutes with the engine running. If it blows cold air you probably have enough refrigerant and then you can chase down a control problem. If it doesn't blow cold then I'd suggest checking the refrigerant first as leaks are the most prevalent failure.

 

Makes sense, I presume I look for this (from XK Electrical Guide)
AIR CONDITIONING COMPRESSOR CLUTCH PI36 1-WAY / BLACK LOWER LH SIDE OF ENGINE
and give it 12V ?
Edit/
Having had a peer it would be a lot easier to short pins 3+5 of the clutch relay which I believe is #15 LH engine compartment box Any problems with this?
Also, looking at the same guide, it seems the pressure switch is not a 4 way jobbie, rather the Ford type varistor which feeds actual pressure back to the CCM - and is probably more likely to go wrong.

 

Without looking at the schematics I don't see any problem with jumping the compressor at the relay (removed) it's probably what I would do without thinking twice about it. Most typically low charge is the culprit. My a/c control panel throws damn near every code possible (native scanner) but it continues to work perfectly.

 

If it ever stops raining I'll do that and report back

 

Well, it was wishful thinking.
I jumpered out the clutch relay and got a metallic 'ting' from the compressor but not much drop in tickover rpm and just noticeably cooler air after 2 mins so I suppose I've got a leak.
I'll take it the 100 km to Dan Dan the Aircon Man next week.

 

With variable displacement compressors and electronic throttles you'll rarely notice much difference in idle spped even with a full charge. The telling is in the poor cooling performance. I just had to put a little over a half pound in mine a week or so ago, not worth looking for a leak - yet. No idea how long it has been since it's last recharge since I just bought the car last spring.

 

Strange you should post this, as I just made repairs after getting 'semi-cool' air for the last couple years sitting at intersections. Code on the AC screen showed 23 also. I was hoping for a pressure switch malfunction (easy, cheap part swap!). My shop down the street, a good 'general' auto repair place found three A/C hoses leaking and the low-charge port as well. He was shocked that my system (and pressure switch was still working) since I had only around 0.5 lbs of freon and I the system takes 1.6 lbs IIRC. Here's a pic of the hoses that I was forced to replace -> 10, 14, and 12+13 (12 & 13 are actually ONE line when buying another one, even though you may see it shown as two on Gaudin's online parts database)

The connections at the ends were not the problem, the leaks were found where the 'rubber, flexible' sections were placed midway along the aluminum pipes. They grabbed a new drier port from Autozone, I ordered new hoses from Nalley before the acquisition by Hennesey and my parts repair bill totaled $320 (the autozone part was like $15)

After the parts were installed, A/C is great, code is now absent, or shall I say, did not return this time after clearing it. I think I've run out of hoses & pipes to replace under my bonnet.

 

Thanks Matt. They look an absolute pain to replace - I can hardly see any of them.
I too was hoping it was the switch but jumpering the compressor relay made the compressor turn but no cooling.
Anyway a 200 km round trip for me to get the aircon checked, but I'll take the missus and we'll spend the night here
Hotel Château de Rancay, Niherne, France. Book your hotel now! - Booking.com
so it ain't all bad!

 

my mechanic said 10 and 14 were easy to replace...but 12+13 in one stretch was a beach...he had to drop the steering rack just a little to get enough room

 

Steve....any updates. You get your problem fixed?

 

Not to panic! Look at the diagram and you will see an item that is marked #5 that is a pressure switch for the A/C. If the Freon goes below a given pressure it will prevent you’re A/C from working. I know this because I along with others had the same problem. Not to say it is your problem but a good chance it is. I say this because I do not have the wiring for 2004 MY car. If I recall all you need to do is jump the two leads in the plug of the pressure switch if the compressor engages check the Freon level and if that is good replace the switch. The switch is located on the coolant line as you look between the engine and the radiator at the bottom. I hope this helps.

 

No, I'm taking it in shortly. Hard to find a competent A/C shop in this neck of the woods but I think I have.
What they're threatening to do is a part fill with lots of dye, then I go back after a few days and they check for leaks. Seems a bit odd but still...
Will post results and costs!