So, I posted something not to long go when I was trying to figure out what was going on w/ my A/C - Well, after trying to charge the cars A/C & change the o rings it wasn't making a difference & I didnt think it was holding freon either.
Well, this afternoon I took it to a repair shop & they did a diagnostic on it to see what was going on & the car had a half lb of freon in the car. So, the mechanic vacuumed the system out and filled with the recommended amount of 2.38lbs and and the compressor kicked on, and so the mechanic said it wasn't blowing cold & so he vacuumed out the 2.38 lbs of freon and added dye to do the due test and topped off the rest of the freon and they looked over the car and there are no leaks.
So -
Dye test - check all ok
Compressor comes on - check all ok
New o rings - check
No leaks - check - all ok
Hold freon - check all ok
All tests normal - check check check!!!!
I have no idea what it could be? The mechanic said he has never seen anything like tht before. So, in turning to you folks! Any ideas of what it could be??? Have any of you seen this before? I'm open to any call outs any of you may have on this subject. This heat this year has been horrible. If I can't fix it anyone want to buy an XJ6 lol jk!

 

Well, you have some very important data missing while you were "checking". What are the system hi and lo side pressures? Does it blow air in the cabin? Have you done the cabin diagnostic test procedure? Why not "check" those?

 

No, I didn't even know what that is? Do these cars have a cabin filter? This is all new to me. This morning when I got in the car turned the AC on and it blew cool air, but eventually warmed up. I reached in the back seat felt the air blowing out of the vents in the back on the arm rest and that blew cold, but the ones in the front got hot. It does blow air in the cabin, but it's coming out warm. They did the pressure tests on both and it was over 50 I believe he said he that's what you mean?! Because he said that they wouldn't work on the car unless it was at a certain level.

 

Jeff- A lil AC101. the compressor copresses the freon from the low pressure gas side to make high pressure gas which makes it hot. The hot high pressure gas then goes through the condensor where it cools, still at hight pressure. that makes it turn to liquid. the liguid then flows through the expansion valve, where it drops pressure and cools as it flows into the evaporator. The outlet of the evaporator discharges back into the low side of the compressor.

So, the question of pressure is to see if the compresser is compressing and the expansion valve is holding back appropriately. If theose pressures are right, (assumong there is no blockage), the evaporator will be cool. If your pressures indicate it is cooling, but you do not get cool air, then the dampers in the dash could be set incorrectly to not flow the cool air out to you, or they can redirect it through the heater core and heat it back up. thatpart of the loop is how the temperature is maintained- Cool the air, then re-heat it. Not too efficient, huh?

There is a procedure to gat a diagnostic for the cabin air dampers by pushing some switches in order. Check the archives for AC diagnostic for X300. If you can't find it, check back and I will look. From your description, it seems like the cabin airflow MIGHT very well be your problem.

BTW, sitting here some 700 miles away, it seems like your AC guy either doen't wnt to work on it for some reasin, or he is grossly incompetent, OR, most likely, I suspect, you have not conveyred his whole story.

 

I am telling you everything he told me - thanks for the "101" I understand how it works. I'm just not overly savvy in AC repair. Thanks for the recap in AC 101.

 

So, have you found the cabin damper diagnostic?

 

Jeff,

Here is what you need to access the climate control and see what if any faults are recorded, and to put the various actuators thru their paces and see if they will do what they are supposed to.

You still need to have someone competent charge that system properly and see exactly what the refrigerant pressures are doing.

Cheers,

 

Thanks xjrguy, I'll check into it, it's just a pain in the *** to find someone in upstate NY to work on these cars and that knows anything about them! Also, thanks for not being a smart *** like sparkenzap!

 

Thanks for the info' xjrguy, very useful.
My A/C system needs a re-gas every year, so clearly something's amiss, probably a leak, but I've had that tested with a dye and nothing was found.
Anyway I'm due to take it in again for a re-gas and have run the diagnostic test and get fault codes 23 & 24. Other than perhaps telling me I need a re-gas do these codes tell me what I should be raising with the workshop where the re-gas is due to be carried out?

 

The 23 is probably low refrigerant, the 24 has to do with the center vent trim control, as you see in the code list. It may have been disconnected at some point, or it has a problem. Try clearing the A/C codes and then see if the 24 returns. If not, no sweat, if it does, there must be an issue there.

Cheers,

 

Thanks very much Steve, I cleared the codes and they both returned.
As regards #24 the center trim control, if there is problem there, how would it manifest itself? What does this control do and how would I know if it was or wasn't operating correctly?

 

This should fill you in.............

 

Not sure about filling me in, confusing me may be more accurate!
I'm not technical enough to fully appreciate what I'm being told here, other than there is apparently a monitoring system which measures the face level temperature output (or something like that!).
Anyway, thanks very much for the information, but in order to proceed it may be useful for me to know what actually is the problem being flagged or more importantly, what is the solution? A change of potentiometer? Some other electrical component? If so, where and what is it?
Thanks again.

 

I tried to do the diagnostic on mine & couldn't get it to do it!? I called a Jag mechanic back home and spoke w/ him and he said he has never hear of it doing anything like this before. I'm stuck here. Not to sure what to do? I am Leary of taking it to a mechanic I don't know because I don't want to get screwed over. ::sigh:: Anyone wanna buy a Jag lol

 

Sh**! I'm sorry, I let this thread fall through the cracks! That's not very nice.

What that's telling you is, that that control in the middle of your center vents will cool your center vent outlet temp relative to the footwell temp, by I think 4-6 degrees F. Turn it to the red dot and it matches the footwell, turn it to center or the blue dot, and you have two steps that are a little cooler than the footwell. The code is telling you there is a fault in the potentiometer circuit to that control.

Hope that helps.

 

No need whatever to apologise Steve, thanks for that full explanation. I had no idea that the face-level and footwell temperatures could be regulated differently. Also, I never understood the red/blue dots on the face vents. I thought it was for hot & cold (logical I believe) but couldn't reconcile this with the fact that overall temperature is controlled elsewhere via temperature setting.
I must dig out the handbook to see if this is explained there! I'm betting it's not.
Thanks again, Steve.

 

I thought that too! Red hot/ blue cool! Oh, I spoke to a Jag mechanic and he told me sounds like my condensers are clogged? How could I fix that? Any thoughts?

 

You need to have a Jaguar mechanic charge the system properly, hook up pressure gauges and go from there. The "over 50" means nothing as that is neither a viable low or high pressure. If all is well with the actual mechanical A/C system then look at the specific climate control dampers by running the diagnostic check in the HVAC system panel like someone else recommended.

Gosh I miss my X300 and tinkering with her in the garage. BTW I only heard of condensers leaking on these cars not clogging up. I had to replace mine.

 

Your welcome to come tinker w/ my Jaguar lol! Finding an upstate New York Jag mechanic has been no fun!