Hey Lads, haven't posted in a while so I guess that means the Jag has been doing alright.
Over the last week however, the air conditioning has decided to stop putting out its chill and after doing a bunch of checks, have started scratching my head a bit on what could possibly be the issue.

Hooked up the gages and did some testing.
At 80F my gages were reading 35-200 and although they could be a bit higher, it is still plenty good for the AC to run.
Fans do come on and compressor clutch does engage. Guess it would have to to get the numbers right
Did a dash diagnostic and it came up with 0, so no codes there.
Hooked it up to SDD and it pulled back a B1969 code for the compressor clutch but it does engage and it doesn't appear to be slipping.

Hoses around the AC system are not getting cold and the interior is hot.
I added enough R134 to get it to 45-210 and that's perfect as per the gage kit instructions at 80 degrees F
Rotated through all of the controls on the climate control to see if anything may have stuck but that doesn't matter when the hoses in the bay are not getting cold.
As I said, fans are cycling normally and actually, outside of no cold air, everything seems to do what it is supposed to be doing.
The only other thought I have is a failed orifice tube so maybe that is what I am faced with.
Any other things I could check first?

Cheers
Bernie

 

I know NOTHING about SDD but............(I only know WDS and IDS)

If you can get to legacy IDS, maybe you could get DATALOGGER to find and read the EVAPORATOR temp?

 

Not sure if SDD is able to get that but I will have a look at it to see.
Being the legacy JLR software - it should be able to get that info but who knows.
Thanks for the tip.

 

My first port of call would be the cabin air temp sender fan. Behind the knee panel on the drivers side . If the fan dont go or its full of fluff the aircon does not work . I used a 40mm computer fan to replace the original with some bogery and aluminium conduit tape

 

I guess there are a number of potential failure points but I keep going back to the fact that even with the system showing all of the signs of running correctly, the piping inside the engine bay is only getting marginally cool. My thought is that if the compressor is running and producing the proper pressures, the piping will get cold regardless of what may or may not be happening inside the cabin. If the various HVAC controls were messed up and not routing air or not allowing cold air in, the piping around the engine should still be cold me thinks. I appreciate the tip

 

The classic first call would be a re charge.

 

Was able to confirm yesterday that the SDD software indeed has a data logger for the HVAC system.
Now I just need to understand what the myriad of sensor details actually means. I will post up some stuff a bit later when I get a chance to sit with the car for a while and take the screen shots.

 

Ok...Here's a weird answer and I have no idea why it could provide an answer, but it might.

So, to hijack your thread for just a moment, I'm driving to work the other day and my a/c goes kaput. Some other lights were flashing too, but the one that was most worrisome was my temperature gauge had fallen to zero. Pulled off the highway (into my goto Jag repair lot) and jiggled the temperature sensor wires near the radiator...They were cracked (my fault...another issue).

Anyway, the A/C came back on and as the engine apparently was running fairly well, I limped back to work.

Long way of saying, check your temperature sensor.

I haven't yet replaced mine by the way, but will over the weekend. Will report back if OP hasn't yet solved the problem.

 

I really wish this forum X100 was SPLIT into the 4.0 1997 to 2002 and the 4.2 engine(2003-2006) with the VID Block cars.(they have almost NO common CAN bus system, VID BLOCK for newer cars)

People post common faults with the 4.0 and others post 4.2 solutions vise versa.(NO correlation)

I will end my rant.

Many iterations of this car.

 

^^ Very true. The 4.0 and 4.2 versions are significantly more different than many owners seem to realize....

 

I agree! It also sucks hoe little information is out there about the different buses used in our vehicles I’m currently trying to chase down a fault in my 06S type R’s SCP bus. Sure theres a schematic in the wiring diagrams but no routing information. Trying to wring out the the SCP bus from the Datalink Connector would be much easier if I knew the routing and splice locations but noooooooooooi. They wont give it. I’m about to make a new post on it so if anybody has any suggestions look at my post

 

I went to multiplex and multiplex advanced diagnostics about 20 years ago when I worked at the dealer.

There are .pdf copies of the student guides that I downloaded from Jaguar Business to Business 'back-in-the-day'.(I still have the actual 3 ring binder PAPER copies also)

Gus will have them on his site because I sent them to him.

Jaguar probably had more info after I quit the dealer but this is all I have.

 

Ok, I have the issue isolated and it makes sense.
Was sitting in the car this evening using SDD to data-log the activity of the HVAC system. Funny thing is that although I had the software up and running, I found the issue without it.
I dropped the AC level on the panel to its lowest value (61 IIRC) and then turned off the AC compressor. Well, guess what - super hot air coming through the vents.
Even though the temp was set to its lowest possible point - but without the compressor running, I would assume that what I would be feeling is ambient air temp which this evening was about 75 degrees F and the lowest setting on the panel is something like 61. Instead, it must have been 100F coming out of the center vents.
So the issue seems to be that my AC and heater are arriving in the cabin simultaneously. This certainly explains why I was not finding any issues with the AC system but was still not getting cold air.
I seem to remember a post I had read a while ago about a valve or something on the firewall driver-side that is supposed to close off the coolant flow through the heater core when the heat was no longer being asked for? Will have to dig around and see what I can find but IIRC, it was the opposite of my issue in that thread. Apparently, the OP was having issues getting heat at all during the cold weather. This is something I had an issue with as well but before I got to digging any further into it, the weather warmed up and I just went to the AC system anyway. If anyone has any experience with this condition, please help me shortcut the research division here and let me know what it is I need to tackle. Weather is gonna get hot here very soon I am sure.

 

RE: 2000 XKR

Sorry to "switch gears" (no pun intended), but the A/C compressor is not engaging with car running when the A/C switch is pressed.

Checked the 10A fuses- O.K. Did NOT check the A/C Compressor Clutch relay... how does one check a relay?

Would a low refrigerant (pressure) be indicated in preventing the compressor activation?

What would the simplistic troubleshooting hierarchy of steps be?

Thanks for the assist....

 

Found the issue folks,

I really enjoy coming back to close a thread with positive news.
I got tossed a bone late last night as I couldn't resist looking into a couple of things on the car before heading to bed and that is when I found - and fixed - my problem.
In the dark and with a flashlight, I wanted to see how difficult it would be to get to the heater valve / pump assembly. Based on a couple of pics I saw, I also was able to locate the control wiring for both the pump and the valve up against the firewall.
Thought nothing of it - I should just pop these connectors off to make sure nothing has corroded or something while I am here. As I went for the 2 wire connector for the valve, it wasn't even pushed all of the way on the connector! It nearly fell into my hand when I went to grab it. Turns out, the locking tab for the connector was broken off or had crumbled off over the years (I had never touched it before), and for whatever reason, it had worked itself loose from the mating connector on the firewall. Super excited, I jumped in the car and fired it up. Cranked on the AC and freezing cold air started coming out. Success!!
As I look back on this potential rabbit hole of a repair, I realized how easy it is to get distracted looking elsewhere for the problem. I had every sensor up on the SDD software - for air conditioning and not one sensor up regarding the heater which I assume is where I could have discovered the issue with SDD if I had looked.
Take your time fellas and ladies, don't and I repeat, DON'T throw money at these things until you have spent the time researching some possible trouble areas and solutions. I am back in business now with my AC and the only money I spent to fix it was a small can of 134 which I believe the system needed a little charge anyway.
Hope this helps others! If you find your AC suddenly stops working, do the following as a test:
-Drop the temperature on the control all the way down until it says LOW
-Turn off the AC compressor and check to see what the temperature is of the air coming out of the vents.
-If the air is hot - you have a similar issue to mine where the AC and heater are fighting each other into the cabin.
That is how I was able to isolate the issue with my system.

Now to head out and see how to secure that connector so that it doesn't slide apart again
Thanks to those that offered some assistance.

 

.

 

So...despite the rants from the certified techs on the forum...and I very much appreciate them, but...
The problem was a bad connector. Not the same bad connector that I found on my 4.0, but a connector nevertheless...
So I was sort of correct...
And have to say, it apparently can't be repeated enough...when in doubt, check the connectors on your XK8. I don't understand why Jaguar plastic/connectors are so finicky compared to other cars. But they are. It doesn't cost anything to visually check connectors. More often than not, it's the source of a problem.

 

Sorry you had a tough time man.
I try to be as self-driven as possible working on these issues. Sometimes the forum really helps but other times, I find that I am the contributor through my own sweat equity.
This happened to be one of those times but there have been plenty of occasions where the lads helped out for sure.
Pretty stoked with the results. AC is rippin' now

 

Well done....

 

Hi can you please post a photo of this temp sensor near the radiator. as I may have the same issue and there are so many sensors!

Thank you

M