Hi guys, the A/C in my 2005 S-Type stopped cooling today. The fan works, and air comes out of all vents, but it's not cold. I have owned the car for about 5 years and this happened twice before. Both times it fixed itself after I restarted the car. That's not the case today. I've driven it four times and nothing.

I looked around the forum and found a couple of threads. One suggested cleaning the temperature sensor on the dash (above the ignition). I removed the plastic cap and saw it was pretty dirty. I sucked out the dirt with a vacuum cleaner. It looks spotless now. But, unfortunately that didn't work. I read another thread about replacing the DCCV valve, but Googling it shows that the valve is the heater control valve and my issue is A/C. The heater works OK.

Anything else I can try? I'm not mechanically knowledgeable. But I'm not afraid to learn and get my hands dirty! :-)

Thanks in advance for your help,

Jose

 

Still may well be DCCV/module, fighting the a/c.

 

Here you go, written for your exact situation:

https://www.jaguarforums.com/forum/s...ol-how-185002/

Lots of possibilities for what could be wrong, so please follow the troubleshooting guide in order. The first step will be to make sure the DCCV is closing properly and shutting off heat when commanded. See post #2 in the guide for details. After that, you move on to other sections based on the symptoms. Be sure to come back here and post what you found.

 

Could be the following. Just preformed on my buddies daughters S Type 8 months ago, no problems with AC since.

 

Could very well be what the other forum members have suggested above.
You have made no mention of if or when your system was re-gassed.
Before you do anything, you first need to go 'back to basics'.
You need to go somewhere and have them check your system for gas (refrigerant). You need to make sure there is adequate oil in the system (maybe needs a top up now). You need to now change the filter. They will tell you if the system has a leak, they can easily find the leak. The compressor may have an oil leak; a potentially huge problem if left too long.
The AC system does need to be 'serviced'.
Good luck.

 

THANK YOU GUYS! You're all awesome! :-)

@jya the car was serviced recently. They did a full inspection. I'm going to go back and see if they checked the Freon. But still, I'm gonna stop by the shop I go to and have them check it. @joycesjag thanks for the TSB. Did I read it right that the compressor valve spring is behind the valve and when you reinstall everything you put the spring IN FRONT of the valve instead? @kr98664 my head is spinning! LOL! But, I followed the instructions on post #2. My biggest concern is that if it's the DCCV, I won't be able to replace it myself. I looked at a YouTube video and it's definitely a job beyond my pay grade. So, in the end I'd be stuck taking it to the mechanic. And, of course, I cannot walk in there and say "I ran a test and it's the DCCV, please just replace that." They'd laugh at me! :-)

 

Hi guys,

I have an update. I took the car to my Mercedes mechanic (he has a small independent shop and works on my 72 Benz) to test the Freon. He said the refrigerant levels are ok, but that the A/C clutch is not engaging. I checked the fuse when I got back home and it's good. I'm wondering if it's time for me to step aside and take the car to the Jag mechanic.

Jose

 

My guess is the problem rezts in the TSB that I posted. Correct reverse the spring and plunger that simple. Unfortunately you need to remove compressor and charge the AC system.

 

He's guessing. The only way to know for sure is to do a full vacuum evacuation and refill by weight. I highly doubt he did that.

On MOST vehicles, you can connect a set of pressure test gauges and make a reasonable estimate of refrigerant quantity. Note I said "most" vehicles. No so with the S-Type. It has a special compressor with a self-regulating output. This will totally skew any interpretation of refrigerant quantity. And it's entirely possible the compressor has already been modified per the service bulletin mentioned earlier. If so, this overrides the self-regulating feature. So not only is it nearly impossible to determine refrigerant quantity, you have to know if the compressor is stock or modified. If your mechanic is comparing the gauge readings to what he is used to seeing on other vehicles, he's gonna end up in the weeds.

The only thing you can determine is if there is enough pressure in the system to satisfy the AC pressure sensor. This sensor has two functions. It shuts off the compressor if the high side pressure gets dangerously high. And it won't let the system run if the system is empty, or nearly so, to prevent compressor damage. But please don't equate pressure with quantity. Refrigerant is weird stuff, and in a closed system will show nearly the same pressure regardless of quantity, unless it's super low. Way more on the subject in the troubleshooting guide.


Okay, now that is something we can work with.

You had mentioned testing the DCCV, but you didn't post the results. Was it shutting off the heater when commanded? This is a very important prerequisite, so make sure the DCCV is good before proceeding.

If the DCCV tested okay (per post #2 in the guide), move on to post #5 for no cooling:

https://www.jaguarforums.com/forum/s...2/#post1714574


It has some very simple tests you can run with a voltmeter and test jumper. The initial steps are all done from the front power distribution box under the hood.

If you'd rather take the car to a shop, I'd suggest an AC specialist. You don't have to go to a Jaguar dealer. If you do take it to a shop, ask if they are familiar with Visteon brand compressors. In addition to Jaguar, these were also used on Ford, Saturn, and Volvo. If the guy has never heard of Visteon, say thank you and keep looking for another shop.

 

@kr98664 Karl, AHA! It's the relay!!! I followed Post #2 and got to the step to swap the fog light relay with the air compressor. I did and the clutch engaged and the A/C started to work!!! I'm on hold with the local Ford dealer to see if they have the part in stock.

I assume I want to definitely buy OEM, right? Amazon has a ton of aftermarket I could buy if the dealer doesn't have the part or if it's crazy expensive (they're about $10 on Amazon).

Thanks so much for your (and everyone else's) help!

Jose

 

Fantastic, glad to hear the fix was so simple.

Those are standard automotive relays. Take the old one to any auto parts store and they can set you up with a replacement. Go with a quality name brand such as Standard, Echlin, Bosch, etc. Stay away from the no-name or white-box stuff, including the house brand at a discount chain.

 

Ok, I called my local Ford dealer. The part in our cars (F57B-14B192-AA) was replaced (superseded) with part # 5M5Z-14N089-BA. The part is $10.83. I called the Jag dealer and the part is almost $40! I assume I can get the new part number from Ford, right?

Jose

 

Karl, looks like we crossed each other! Ok, since the part is a standard relay I'm pretty confident that the new part number from Ford is gonna work. I'm gonna go for it.

Jose

 

Congrats Jose!!

 

Hi guys, good afternoon.

I picked up the relay on Friday and installed it in the car. The A/C is working perfectly now. Thanks for all your help! I really appreciate you all :-)

Jose

 

Thanks for the follow-up.