Today was the first fairly lengthy road trip (225 miles) my 2005 S-Type has done since early November. This afternoon was also the first mild day since about that timeframe when the car's A/C has actually been needed to cool down the solar gain taking place in the cabin. Unfortunately we got nothing but ambient air blowing through the vents this afternoon, no cooled air at all. The factory compressor failed in May 2010, I went with an Omega replacement unit at that time, and it has functioned perfectly since it was installed. Sure hope the replacement compressor has not also failed (although it came with just a two-year warranty). I'm hoping I just need a 134a refrigerant recharge. Perhaps my factory DCCV has finally failed internally although it has not leaked a drop of coolant externally. Guess I have some investigative work to do during the next few days. Any advice from you HVAC gurus would be much appreciated....

 

Hi Jon,


In addition to checking out the DCCV, you should also check out the CCM as it usually gets fried when the DCCV goes out. If you're handy with a soldering iron you might be able to repair the CCM. There is an old thread on this board with pictures on how to do this. Another possibility is that the evaporator is bad. Good luck.

 

Yep, I'm aware of the DCCV/CCM damage combo. But I believe both of these components are performing as designed. The heat in the car is normal. Even distribution across all vents as usual. Yesterday I reviewed the fuse box diagrams in my owners manual then pulled, examined, and re-set all five fuses that control various components of the HVAC system. I'll take the car out on the road later today and see if anything has changed as a result. We're back to cooler temperatures now so any A/C issue will be harder to determine. Thanks for your input....

 

Hi Jon,

You might want to check out the evaporator then. I had the DCCV, CCM and evaporator replaced on my S-Type a few years ago under warranty. What happened was that the DCCV and CCM were replaced together, and then a couple of months later, the evaporator went out. I was getting ambient cooling only, but the heat worked fine as I recall.

 

Thanks Mike. I'll add the evaporator to my checklist. Sure glad I'm having to troubleshoot this issue in February as opposed to July....

 

A fair check of DCCV & RCCM is can you get warm, hot, and very hot air i.e. is it able to move the solenoid valves.

 

Good info. Helps me too.

 

Evaporator problems are very rare on the S Type and that's good.

It's a real bear to change the evaporator out as most if not all the dashboard has to come out. I would try everything else before changing that!
.
.
.

 

I usually check pressure first, it should be about 80-100 PSI. If system is empty, I pump air and try to find a leak.
If system seems full, I get electrical diagram.

 

Update:

Due to the rather cold weather in our neck of the woods during February and into March, I moved my S-Type A/C issue to the bottom of my punch list and concentrated on other tasks. Now that afternoon temps are suddenly climbing into the 80s, I'm sweating like a pig in this car with the windows down and must turn my attention back to its faulty A/C. I've decided to have the same shop that replaced my factory compressor back in early June 2010 do a thorough system check, evacuation, and recharge tomorrow morning. $90 plus tax. Not too bad considering other area shops quoted me from $150 to $200 for the same service....

I sure hope a 134a recharge is all my S-Type HVAC system needs. We'll find out tomorrow....

 

If pressure is low, leak has to be found and repaired.
Does compressor clutch spins when you turn AC on?
Price of freon is $3 a pound.

 

Update:

The A/C shop found a leaking O-ring on the high-side line. System evacuated, new O-ring installed, system recharged with the proper amount of R134a (1 lb. 11 oz.) along with the appropriate compressor lubricant and leak-detection dye. System is now blasting arctic-quality air again. $97.50 total. I'm very happy again....

 

Always good to find a problem and a nice simple one too!
.
.
.

 

Congrats Jon,

You got over like a fat rat. Basically it sounds like a fairly reasonable A/C service at the right time.

I dodged a major bullet when my touchscreen started acting up. None of the buttons on the screen worked right and a new touchscreen is about $3500. However, the problem seemed to correct itself and now everything works OK. I have a theory that one of the cans of brake cleaner I had in the spare tire well got next to the battery and fuse box and that might have caused issues. After I removed the can life was good.

 

Mike,

More Jaguar voodoo going on in your trunk I guess. Let's hope your touchscreen stays normal now. I believe that the plastics and the electronics in these cars will be the factors that will eventually cause me to either sell them or donate them to charity as a tax deduction. I continue to hope that the cost/benefit factor that causes me to finally make that decision remains well into the future. Time will tell. Enjoy your XJ8L....

 

Jon! Did you see them removing O-ring and pumping system?

 

No, I did not stay and watch. I left the car with them for a half-day and returned to pick it up when they called to say it was ready. I trust them. I've used their services several times in the past. As an AAA member, I get a 2-year/24,000-mile warranty on any work they do for me. If I have ANY issues with this HVAC system going forward, they know I will be back in a heartbeat and require them to make it right....