Hello all. Sorry I failed to close the loop on this thread earlier. You guys have it nailed: it was the evaporator temperature sensor. My mechanic never even hesitated when I described it to him -- he said he encounters it a lot. When the sensor failed, the system never cycled off, so after a while it would ice over. It cost me quite a bit more than the $20 that kr98664 suggested, of course, but I'm okay with that. My joints don't handle crawling under the dash as well as they used to.

KLK239, if you're up to the challenge, it sounds like you can swap out the evaporator for a pretty small cost. Even if you take it to a mechanic, it's not terribly costly -- a couple hundred bucks, in my case. Obviously, I didn't enjoy spending the money, but I was prepared for it to be a lot worse. Good luck with it!

 

Good to know the cause & fix - thanks.

 

Thank you so much for the follow up, Gary. I can't seem to find the emoji that bangs its head against the wall! It makes the most logical sense that it is the evaporator temperature sensor. I think I will be able to change it out as I am a fairly petite woman. I pray this is the fix. If this solves my issue like it did Gary's I should have the FINEST AC ever given that it is practically all new!


I still hear creaking in the dash so would not be surprised if I have a blend door issue. One thing at a time...


kr98664, thank you for the part number info.


I will try to replace this weekend or next and will report back my results.


Best,
Kerri

 

Kerri,
Beware it uses 3 of that part number (well, the 03-sub facelift cars do, I assume yours may, as well)
2 on the left, one on the right side of the tunnel. The Evap temp is one of the ones on the left, but I can't remember if it is the hard one to get to...or the harder one. Sorry. One is for evap temp, then one for driver's side temp and one for Pax side temp on dual-HVAC systems. (Again, not familiar enough with the pre-2003 cars to know if they have the dual system)

 

There's only one evap one though, I think. I'm thinking it can't be in the cabin to detect icing up...

 

I ordered three. My understanding is that there are two sensors on the driver's side and one on the passenger side.


Forgive my ignorance but what does 03-sub facelift car mean? I believe you mean 99-02 s-types before they changed the grill, etc. I have looked at the JaguarClimateControl website and their photos. 2000 s-type do have dual HVAC so I am hoping the 2000 is the same or at least similar. I can't find photos/videos specific to my year.


While I am at all of this, I think I will vacuum the air cabin air temp sensor.


I love/hate your decription of the "hard one to get to...or the harder one." Should be interesting.

 

Yes, that is correct.


Please see post #7 in this thread for more details of how the evap temp sensor is part of the compressor control:




https://www.jaguarforums.com/forum/s...c-help-148484/




Post #9 in the same thread has a picture of the sensor and a description of the location.

 

Sorry, a colloquialism from the industry in which I work. I mean Model Year 2003 and subsequent (later) builds. "Facelift" is a slight misnomer as well, because the 2003 looks mostly identical to the 2000 on the outside. The dash layout is considerably different, however. (Naturally, for the UK, that is MY 2002.5 and beyond...but that only serves to confuse things further)

 

FYI, I managed to find the invoice from having my evaporator temperature sensor replaced and the shop listed the part number as "XR8 53162," rather than the "MotorCraft YH1504" referred to earlier. I don't know if that's significant or if it's just the difference between the Jag part number and the Ford (MotorCraft) number. If they're interchangeable, go with the Ford, since it appears that putting a Jag part number on it boosts the cost by about $100.

 

03+ is basically VIN M45255-on.

(and yes in UK is 2002.5MY-on)

 

This is the part:


Amazon mistakenly calls it ambient temparature sensor.

 

Leaping cat - that is the exact part I ordered.
Gary- thank you for digging out your old invoice. According to earlier posts I have read,
XR853162 replaced XR83729. At least one poster (ndy4eva) has successfully used Motorcraft YH1504 as a replacement. https://www.jaguarforums.com/forum/s...-sensor-35014/

 

Another confirmation that YH-1504 is the same part.

 

Yep, that's what I'm running in my car. All three positions.

 

I replaced all three evaporator temp sensors this morning. I looked at the cabin air temp/humidity sensor above the ignition. It was quite dusty and dirty. I used a Q-tip to clean what I could. I am going to buy aerosol electrical sensor cleaner today.

Question: Can I pull the cabin humidity/temp sensor out to clean or should I just spray into the cavity?

This afternoon I will take the car on a longer drive and report if any of this solved my problem.

I also performed the "manual blend door reset" I found on the forum. I still hear creaking as the doors switch between face/floor/defrost.

 

Success! I replaced all three evaporator temp sensors and cleaned the air cabin temp/humidity sensor.

I went for a 1.5 hour drive. I immediately noticed that I was able to get temps in-between LO and HI. Previously 68, 70, 72, etc. all felt ice cold and I could only get heat on HI. After 1.5 hours I had no diminished airflow. The vents were still blowing strong! I will feel even better when I can replicate this on a hot day. Temps are pretty mild right now but I did have this problem with mild ambient temps so I feel pretty confident it is repaired.

Many thanks to all of you. This forum is outstanding.

 

Groovy! Glad to hear the good news. So many threads go unresolved. It's always nice to hear feedback about what fixed (or didn't fix) the problem.

 

Great news, Kerri!
Now if you have a meter, measure the resistance of the 3 sensors removed, to identify the bad one(s). I'd start with all three at room temp and if one is significantly different than the other two, that's likely bad, toss it and save the other two for future use. You can get fancy with the fridge/freezer and a heat gun and try them all at various temps and compare to a temp-vs-resistance chart (I believe someone posted it for that sensor somewhere, here - or you can probably find one using the motorcraft part number) for greater accuracy, but it's not terribly likely that two would fail in the same manner at the same time, so if you have two in agreement, they're likely good.