So today I found myself challenged to a race on the interstate. So much fun! 130+mph and better driving later and the challenger (some new sharp and sporty Kia) was somewhere way back in my mirror.
Then got where I was going and my AC wasn’t blowing cold air. Got home and the screeching sound of a bad compressor was silenced upon turning off the ac.
So I won! But I broke my ac in the process I think.
I assume the lesson here is to turn off the ac while racing 😂
Lesson Noted.
Della Rose is scheduled for service at the dealer come Tuesday morning, will advise upon completed repair as always.
As you all know, this is a pita to replace. 💰

 

Trying to attach a video...

 

So I went out to the car to try and get video of the noise and problem, in hopes of making a post that had value to those who may search for AC trouble in the future.

And, now the AC works! Lol

If I rev the engine I can make it squeal like before a little at high rpm, but I’m not going to push it.

Weird!

 

Could the noise be a slipping serpentine belt?

If the compressor locked up at high RPM, it may have chewed up the belt. Even if no damage is visible, it might be worth changing as a precaution.

 

Have you had any refrigerant added recently

 

From my notes when I wrote my HVAC troubleshooting guide, this may have accomplished automatically.

In addition to other conditions, the AC compressor clutch is switched off at Wide Open Throttle (WOT) or if engine RPM is above 5882. Unfortunately, it may have violently re-engaged when you let off the gas and the RPM dropped to 5881, which is still screaming.

I still wonder if the belt took the brunt of the abuse.

 

I have an appointment at the dealer on Tuesday, so I can run these possibilities by them when I drop Her off.

Thus far from the forum I have: serpentine belt and check ac gas. Both of which the dealer can check out.

Outside of the forum, My mechanic friend who has done a lot of work on the car noticed the display for the climate control was blinking when he brought me the car (after the coil replacement, that’s another monster thread https://www.jaguarforums.com/forum/s...-212314/page2/)

The blinking is intermittent and is resolved by tapping the display lol.
He notes that I have had some electrical things arise before, and was even suspicious when we replaced the compressor.
I note that I did replace the stereo, So I messed around in there quite a bit before and could have left something just a little loose without realizing it.
The idea is that the climate control mod sends a signal to the ac clutch to engage, and if the signal is weak due to a short or bad connection the the clutch engagement would also be weak (or partial). This could lead to the slipping clutch and possibly burn the clutch out. I don’t know if that is how it works.
He thinks this could all be related to a known problem on the circuit board within the climate control mod, and wants to take the mod out and see if he can fix the circuit board.

He lives an hour away.

I am leaning toward going to the dealer that is 20min away, hoping that whatever they fix will have a warranty. That, and they already said they would give me a loaner car... which could be very cool indeed.

Either way, it’s my Dad’s birthday and the ac is working. So it’s party time! I will advise when I know more, as always.

 

Excellent....dad bday top priority....and you have options for your car diagnosis and ac currently working

 

What year is your car?

The only known problem that comes to mind with the control module is on 2003+ cars only. The DCCV can draw too much current and damage the associated part of the circuit board inside the module. This only affects the operation of the DCCV, and not the compressor clutch or display.

Unfortunately, when the DCCV circuit is broken, by default the two internal valves spring open and route maximum coolant flow to the heater core. This is a safety feature so the defroster works. The AC portion of the climate control system continues to work, but the volume of heat overwhelms it. The typical complaint is no cooling, but it's actually caused by full heat when it should be off.

Check out this repair service for more details, pictures of damage, etc.:

https://jaguarclimatecontrol.com


Note his rebuild service includes adding overcurrent protection in the DCCV circuit. But I think your problem with the display blanking is a separate issue.

For troubleshooting, try this. Next time the display blanks, look at the buttons on the panel. Do you lose the lights with the buttons? Even with the display blank, can you switch modes, such as selecting defrost and the airflow changes accordingly?

If the panel is blanking because the external connector is loose, the entire module (not just the display) should go dead.

If the panel has an internal fault affecting only the display, the other features should still work. In that case, you might get lucky and find a cold solder joint or loose internal connector affecting only the display.

If you want to open the module, the link above has instructions to prevent damage during the process.

 

Blinking climate control display on the 2003 and subsequent cars is a common issue. Both of mine do it, as well as a 3rd climate control module (a spare) I have. It may or may not be blank; if it is, a tap on the screen normally restores the display, although that may set it to blinking. It may also wax and wane as you have your finger on it.

As I said, I have 3 modules that do this, and not one exhibits any other fault as to operation of the HVAC. I would not be surprised to find the CCD blinking in the 2003 parts car with a knocking rod next time I fire it up to move it about. But for now, I only claim 3 of 4 blinkers. After all, flashing lights and displays, it's just what Jaguars do. Search the forum for "flashing lights" if you are a disbeliever. In fact, a friend and I half-jokingly refer to emergency vehicles, with their impressive array of flashing lights, as "fake J'aaags"

 

Interesting. I wonder if this can be easily repaired by cleaning where the display makes contact with the circuit board. Here's the official process for restoring the LCD display on certain Fluke multimeters: