Hi guys,
Can't seem to work through my AC problem.
- Checked fuse 32 in under the hood box
- Replaced DCCV (brand new ford equivalent)
- Replaced CCM (Used that shows no repairs and continuity tester shows OK)
- When AC button pressed on can see RPM change slightly, when AC button pressed off, can see RPM change - so I'm of the opinion that the compressor is working.

Looking at DIY @ Jaguarclimatecontrol.com, it appears that there are a few other things I can check/change, but looking for some logic that matches the parts to my symptoms.

Air conditioning just stopped working after a long drive. Then, on next start several hours later, it worked fine and worked fine several more times. But, on occassion, with increasing frequency, regardless of length of drive, it would not work. Now days, it never works.

Does that sound like a AC Pressure sensor/switch?
Or, the Evaporator temperature sensors?
Or the In-cabin temp /humidy sensor?

Would appreciate a little direction. Thanks, Joe

 

How much do you know about the A/C system?

If you don't have the skills and at least a set of pressure gauges you are shooting in the dark.

Take it to a dealer or if you are brave an A/C shop.
.
.
.

 

Thanks for the input. Taking it to a specialist is one course of action that I may well pursue, but not just yet. I'm willing to give it a little more thought and effort.

An example of the logic questions that I am looking to be applied, include thoughts related to the Evaporator temperature sensors. There are three, two on the driver side, one on the passenger side. The testing procedure calls for measuring the resistance of each sensor. However, before doing so, I wondered if the failure of one sensor would shut down the entire AC system, or only the side that the sensor was mounted.

Another example, related to the in-cabin temperature/humidity sensor, includes the understanding that this sensor helps keep the interior at the setting of the Climate Control Module. However, if the CCM temperature is set at its lowest, then I was under the impression that this sensor is ignored.

Are these thoughts correct? And, how about a diagnostic test for the AC Pressure sensor/switch?

Thanks again,
Joe

 

No. I have had problems with those evaporator temperature sensors and they will make the A/C act funny but not shut it down. Still good to check. As I have posted before be sure and clean the small sensor behind the grille right above your ignition key. Mine was very dirty and a quick spray with carb cleaner got it cleaned up. The small grille pry’s off but the sensor is a bear to get out.

I still don't see if the compressor is turning? I know you looked at the engine RPM but look at it to be sure.

Again without taking the high and low side pressures we really can't help.

Please check that the A/C compressor does not have any yellow/green staining on the bottom side. If it does and this is real common. Your compressor is leaking and needs to be changed before all the oil is gone and the compressor eats itself.
.
.
.

 

I would concur with checking the high/low side pressure. It may as simple as recharging the freon. If it checks out, then do the checks recommended in earlier posts. A few years ago I had my DCCV, CCM and evaporator replaced under warranty.

 

+1 - check pressures and report back. Be sure to also notate ambient outside temperature as well.

 

+1. You need to look at the compressor and make sure the clutch is engaging first and then get pressure readings.

 

Okay, I'm wrong, you're right. Why the RPM changes when the the AC control panel button is pushed "on" and then changes again when the button is pushed to turn it "off" is a mystery to me, but in fact, a visual check of the compressor when the AC light is on did reveal that the clutch was NOT engaged. The clutch is not turning. There is no green fluid leak.

I see on the 2005 Lincoln LS, the clutch is available as a separate piece, heck, even the clutch coil is available separate. Anyone have any idea if those parts will work on our S-type? If so, is anyone aware of a diagnostic test that can help me narrow down my work?

Appreciate your thoughts.
Thanks,
Joe

 

There are several reasons it may not be engaging. The most common is a low freon charge which can be confirmed with pressure readings. If they are low, you may just need to recharge the system. If they are not low, then I would check for power at the compressor and go from there; but chances are its just a low charge. Also, with the engine off, you should be able to spin the compressor clutch by hand rather easily. If it is difficult or impossible to turn, then it is binding and will need replacement.

 

Thanks for the information. Really appreciate it. My understanding is that to read pressures, the compressor needs to be running. Somewhere on the forum I read a posting that mentioned the same dilemma, which they addressed using a suction system, but I am not familiar with that.

Regarding the clutch turning by hand, it will turn, but not as easily as another car I have. Can it be cleaned/lubricated? I'd be happy to replace it, if that can be done using the Lincoln LS clutch (the replacement compressor kits are the same, just not sure if the Jag original equipment has a clutch that is serviceable.

Help me out, thanks, Joe

 

You can still hook up the gauges and get pressure readings without the compressor running. If the freon level is too low, the pressures will be too low for the compressor to come on.

 

Before Passenger side cold and Driver Hot. Had that issue before also.


Went to Dealer ...said replace DCCV . ( Wanted $695).


I have DCCV replaced ( bought new Bosch valve online for $125) checked for continuity...Had the RCCM repaired for any burnt circuit ..( reviewed Jaguarclimatecontrol website) ......but now driver side runs cold and passenger is hot....!!..no matter what thermostat settings.




Notice in my older DCCV ..one valve was stuck with dry gunk in it . The Freon checks ok and compressor kicks in.


One more thing ...still the original battery ( +9 years)..had it checked at Autozone...holds charge.


What Gives ??

 

Yes. I have posted this before because I own both cars but the Lincoln LS V-8 uses the same compressor and clutch. So you can use the LS parts to replace the clutch if you have a V-8 powered S Type. The 6 cylinder cars use a smaller A/C compressor and they do not interchange.

Glad you had no staining and now you know the compressor is not leaking (at least it's not leaking oil!).

Before doing any work make sure the clutch is getting power. In the old days I would jump the low pressure switch for just a bit to see if the compressor would kick in. But on the S Type I don't even know where the low pressure switch is!!

But you can unplug the A/C clutch and then use a volt meter to see if it's getting power.

You did not say how many miles are on the car but the clutch is a wear item and back when I had less money I would shim the clutch to the proper clearance. This usually was a short term repair because the clutch metal faces do wear with time. I recommend a new clutch and if you are around 100K miles I would get a new compressor. They are cheap on EBay since they also fit the Lincoln LS.
.
.
.

 

Took T-Bird up on his first recommendation, "go see a specialist"

Still wanted to report back for those following the thread. FYI, my 2005 S-type has 140K.

Specialist stated there is freon in the system, pressure was 110psi, which though low, is enough for the pressure switch to allow the compressor to turn on. Then, because the clutch would not engage, they checked for power at the compressor. Reported back 12V. Their conclusion is a that clutch is shot, and maybe compressor too. They claim to replace clutch and clutch coil, they would need to remove compressor from car and because of that, they would need to replace dryer, vacuum system, flush, re-oil, etc. In total, because of all that work, they recommend replacing the compressor too because most of the associated work would be done anyway.

Can anyone confirm that the compressor on the 4.2AN has to be removed to replace the compressor clutch and clutch coil?

Thanks again,
Joe

 

The factory compressor on my 2005 3.0 slowly failed in May 2010. The replacement compressor (not OEM) has been fine ever since. These S-Type compressors do have a failure history here on the forum. I'm betting you need a new compressor. And most A/C shops do insist upon replacing the receiver/dryer at the same time....

Good luck and keep us posted....

 

Thanks Jon, but my understanding is that the later S-type, including 2005 (mine), used a different compressor than the well documented spring valve compressors on earlier cars. In any event, not sure that answers the question of whether the clutch can be accessed without removing the compressor.

Anyone else?

 

That has been reported but it's wrong. My 2005 STR had the spring valve on the compressor. So take that with a grain of salt!! The real answer is it depends. I will say the Chinese replacement compressor I put in did have the plate with the spring behind it.

You could change the A/C clutch in the car but it would be tough. I completely agree with what your shop recommended. If you can't do it yourself. At 140K miles your compressor has done its duty! Time for a new/remanufactured one. To save money you might suggest to the shop to source a 2005 Lincoln LS V-8 compressor. I know at Jaguar they wanted over $800 and I got my Chinese one on EBay for around $250 with the dryer and oil.

You do know about the weird dryer we have in the 2004 and up S Types? The fabric bag? It only costs about $25 for a new one but it's a bit tough to install. Before you have the shop do any work ask them where the dryer is located and what it looks like. If they say it's inside an Aluminum canister then they have not worked on a system set up like yours. The early cars from 1999-2003 have the old canister type dryer.

For some good pictures and further explainations try this one.

https://www.jaguarforums.com/forum/s...-common-67271/
.
.
.

 

Does The Sensor Just Pull Out Or Is There A Trick To It? I've Removed The Grill But, Don't Wanna Damage The Sensor..

 

From what I understand the sensor behind the grille has to come out the back. That's why it's so tough. No need to remove it for cleaning.

When I cleaned it I stuck a paper towel in back/around the sensor and then sprayed a bit of carb cleaner on the sensor and used a Qtip to lightly scrub the dirt off. It was dirty enough that I could see dirt stains on the white paper towel.
.
.
.