Gents:
Thanks for all your advice and help. The jaguarclimatecontrol.com website was indeed helpful, although they only repair the later control modules (2003-2008). The earlier CMs such as my 2000 S type has is a sturdier unit; this probably explains why I did not find any faults with it. The evaporator sensors did come out by prying with a screwdriver. They are all good; all had the same resistance at three different temperatures. The cabin air temp sensor, behind the small grill above the ignition key was very dirty; cleaned with air can and throttle body cleaner. I checked the voltage to the DCCV at the pin connectors per jaguar climate control's instructions although they don't give what the readings should be and their website says they only do late model CM repairs, so I did not seek their advice. As my DCCV was relaced just about four months ago, I don't think that is the problem. I then checked the refridgerant level; it was indicating slightly low. I added one can about three months ago and it seemed to fix the hot air from the right side vents. There is some green dye on the bottom of the compressor; looks like it may be seeping where the flange of the front compressor section is bolted to the compressor body. I cannot detect any leaks with my freon leak detector, but I added 14 ounce can of R134 with seal conditioner and it seems to again have fixed the problem of hot air from the right side vents. All vents were within 2-3 degress F of each other; about 60F (it was 95F in interior; a 35F drop is pretty good.) The compressor has some noise, but I checked my Honda and Chrysler compressors with stethascope and I think the Jag compressor noise is normal. During the 25 minutes or so that the AC ran with 95F outside air temp, the high side pressure, which started at 200psi only got to about 225psi, so I do not think the espansion valve or drier are blocked. I plan to drive it for a while, look for more leaks on compressor (I cleaned off the green dye) and see if symptoms return. If system looses freon again, I guess I will replace the compressor. Interesting, there is no dye residue coming from the compressor seal, only the lower flange area; if the seal is leaking, which I would suspect is more likely than the flange, perhaps it is dripping down??. Also, pehaps the doors are not correct, or the DCCV is intermittantly sticking for the right side. I am leaning toward the refridgerant leak theory and when the system is low, it can only cool the left side. One more thing, before I charged the system again, all vents were blowing 45F cold air. After engine was warm, I ran the interior temp selector to 85F, all vents went hot, then back to LO. The right side vents stayed hot, the left vents went cool. I then clamped off the coolant hose from the thermostat housing to the DCCV. After several minutes, the right side vents went to about 60F. I guess this could mean there is a problem with the right side of DCCV or possibly a door problem. Or it could just be that once the heater core is hot, there was not enough refridgerant to cool the right side. I think the left side of evaporator gets the condensed refridgerant first. Please excuse the long rambling text; believe it or not, this is a condensed version! Thanks again, I appreciate all the suggestions.

Best Regards, Jim
2000 S type 4.0L

 

Hi Jim,

I have the same compressor symptom on my 00 S Type 4.0 - slight seeping leak from the front of the unit. Any UV leak detected (even visually) at the compressor, whether the front or rear or even seeping is indicitive of a refrigerant leak (even if a small one) and is a tell tale sign your compressor is on it's way out and could be the source of your leak.

I would also suspect one of the solenoids sticking or sluggish in your DCCV.

Just my $0.02 - thanks!

 

Abonano, Thanks. The next day, same problem; 50F all vents on start up. ran temp sel to HI, all vents hot; ran temp back to LO, right vents stay at about 90F, left vents about 60F. Haven't checked refridgerant level, but it was only one day after charge. I think it is the doors, a sticking DCCV, or improper signals to DCCV. Even with the likely refridfgerant leak, I don't think that is the main problem. When I clamp off the hose from the thermostat housing to DCCV, the vent temps return to about 50F after several minutes. If anybody knows how to diagnose the DCCV without taking it out and how to diagnose doors, please let me know. I won't be able to get to it for several days, but I can only work on a problem I can't solve for so long! I worked on XJs at dealerships in the 1970s. They have a gazillion vaccuum hoses for door/ valve control. I wish the S type was that simple!

Jim
2000 S Type 4L

 

Jim, Sounds like one of the solenoids in the DCCV is not responding to closing (to shut off coolant flow) after initial opening to allow hot coolant to circulate. The best way to diagnose is to clamp up the DCCV hoses - but almost sounds as though you are headed to replacing the DCCV anyway... Be prepared - changing it out is a real PIA... as far as vent temps are concerned - air coming out of the vents with the A/C on should be in the 42 - 49 degree range...again, just a range as it is hard to pinpoint vent temps as outside air temps will influence vent temp output. 60 degrees sounds like a A/C refrigerant issue or DCCV sticking allowing hot coolant to circulate raising the vent temp.

 

I would stop screwing around and just change the DCCV. It's a known problem and with the age of your car it's almost guaranteed to be bad.

The doors in the system are a much more rare failure.
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Clubairth1, I know the DCCV is prone to failure, but I just replaced it about three months ago. The condition I had then was no heat. New DCCV fixed the no heat problem, and perhaps the new one is defective, but I am trying to determine how to diagnose it first. If it is indeed defective, I think Rock Auto may replace it at no charge. Are replacement DCCVs also prone to failure?? Thanks.

Jim 2000 s type

 

The DCCV normally fails open allowing hot water to pass when it is not wanted.
Clamp the outlet hoses shut and you have the same effect as a closed valve.

 

New DCCV's have failed after replacement but no are not known for that.
Just something to check and keep in mind as your troubleshooting.
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Gents, Just checked ac freon charge, to see if it had leaked out. No leaks noted and the pressures indicate it has a full charge. I guess I will change DCCV again (just changed it five months ago). Will inquire with jaguar climate control for diagnositic help, and Rock Auto for possible warranty claim on DCCV. Thanks, Jim 2000 S Type 4L

 

Finally found the problem, I think. With some diagnostic help from jaguar climate control, found good continuity to DCCV connector. Then checked manually grounding outside pins on DCCV with 12V to center DCCV pin. The left side had .82amp and could hear solenoid click. The right side (always blowing hot air) had .76amp when grounded, but there was no clicking sound, so the solenoid is apparantly stuck in the open (hot) position, which would explain the condition. Ordered Motorcraft DCCV from Amazon; about $155. The defective DCCV was Four Seasons (for 2000 Lincoln LS) for about the same price. It only had a 120 warranty and even though it failed right after installation, it took me 5 months to figure it out. Because the DCCV was just replaced, I kept thinking it was something else.... Thanks for all the help. Happing Motoring, Jim 2000 S type 4L

 

Thanks for the feedback!!

We are just guessing without seeing the car. Plus most people don't do a good job of documenting what is actually going on. I thought you did a detailed job describing your cars symptoms.

That make a HUGE difference to the quality of answers you get. It's very common for someone to post my car has a problem but I won't give any details and I will come back in a day and complain I did not get any help. It just can't be done and I generally ignore these Bozo's.
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I don't have too much skill with testing electronics. Can anyone tell me how to perform a resistance test on these sensors? I have a multimeter set to ohms and I'm using the two probes and touching it against the two prongs on the sensors, but Im not getting any readings. What am I doing Wrong and what should I be seeing?

 

At 25 C (77 F) they should read 30 kiloohms.

 

Thanks. I now have someting to look for. Unfortunately I'm unable to get any resistance readings from all three sensors. They could be all bad since I just changed my DCCV and could not find any burnt traces on my CCM (checked for continuity of all the pins) and still only have cold air coming from the driverside center vent and the furthest right (albeit a few degrees warmer than the center). Am I testing these sensors incorrectly?

 

Try other ranges on your meter.

 

Thanks Jag V8,

I got it to read by switching my multimeter to read "200K" using a craftsman 82141 digital multimeter.

At room temp around 74F (23.3c) I'm getting readings of around 33.0 for two sensors (the ones from the drivers side) and the other sensor (from behind the glove box) is reading around 26.

I decided to leave the sensors in the fridge for about 5 minutes and the readings I got from the two sensors were 41.2 and the one behind the glove box was reading 32.0. Im thinking the one on the passenger side is bad because its the one blowing the warmer air. I will order a replacement and report my findings hopefully by the end of this week.

By the way I found a chart that was pretty helpful on understanding what readings I should be getting depending on the temps. Its not the exact plug that we have in the Jag, but it looks darn close. I just used it as a reference.

http://www.ge-mcs.com/download/tempe...20-532A-LR.pdf

 

I'm having the same problem with hot air from AC vents. I was able to removed the passenger-side sensor behind the glove box. Just wiggle it out of the evaporator. But getting the sensor to release from the wiring harness is a chore. I never did get the driver side sensors to separate from the wiring harness - just not enough room for leverage unless you have arms like a crab. Very tight space to work. I'll try again this weekend.

One question though. How do I test the resistance on the sensors. Put my multimeter leads on each prong in the sensor or ground one lead of the multimeter and use the other lead on one of the prongs in the sensor. Or am testing resistance of the wiring harness that came out of the sensor.

Thanks for any help. It's getting hot where I am. Need some cold air.

 

You do know the fault is almost always the DCCV and often it burns out the module....

If you didn't start with those you're probably wasting a lot of time!

 

Yes, I'm aware that the DCCV and CCM are probably the culprits, but trying to convince myself otherwise, since I spent around $2700 in June of 2013 having both replaced. It seem that the "new" parts lasted a few weeks past warranty before giving me trouble again. I was hoping it might be the sensors, lie or overcharged freon levels, a fuse or something else. Will be checking other possibilities this weekend.

 

Ouch! That's horrific.

The module is easy to get at in case it has burned tracks. Just behind glove box.