Hi, I had this - twice, we replaced the Dual Climate Control Valve, but actually it was just corroded connections to this unit which lives under the front engine sump protector panel Drivers side (UK - Passenger side US). Should flick between 2v and 14v when you cycle between cold and hot. The Ford made unit is from US Lincoln (Continental and Town Car I think) where this problem is well documented on their forums. On the S type (esp UK models where it is on the offside) the unit is a bit more exposed to salt etc. Easy fix once you know how!

 

can you explain this a little better? my car has the same problem, thanks!

 

Hi Mike E, Your symptoms sound exactly like the corroded wiring harness problem - there are quite a few references to it in this thread. Basically the voltage drops to the solenoids that control the dual aircon valve(or triple valve if you have the aux winter heater) and they stick in hot or partially hot position. Your mechanic needs to do a thorough strip back, replacing any dodgy wiring and checking the voltage variations with a meter whilst moving each side control from Hi to Lo.

It is unlikely to be the valve itself although I understand the plungers can perish, unlikely in an 03 car.

This valve came off a Lincoln (Town car I think, not familiar with US cars!) where it was safely tucked away up in the engine bay. On the Jag S type they put it right down close to the road (US drivers side, UK passenger side) where it gets all the salt and water - even with the engine guard. thats why the wiring rots.

Cheap fix though and a good dose of amalgam tape fixes it for good(common use is to wrap up satellite LNB connections - so head to Maplins (do you have Maplins - Radio Shack? Tandy?).

Even here in Scotland driving around in the summer with the heating on was pretty unpleasant! Hope this helps. Brian

 

i had the same problem, where my heater would blow hot most of the time and cook me. It also caused issues when i was in cold weather, since it would vary form hot to cold and cause windows to steam up and such like...

I found JagRepair.com - Jaguar Repair Information Resource where there is an article on the heaters. Followed his guide and cleaned the temp sensor in the dashboard and now it all seems great.....my sensor was covered in crud and lint, sprayed it with some carb cleaner and wiped it with a soft cloth and it seems to have done the trick...

hope this helps!

 

On my S-type, the problem was in the integrated circuit board under the dash (left hand side, left-hand driving). It had a crack so the signals got mixed up and only hot air would come out the ventilation, whatever I did.
My garage got the board fixed through a 'guy' that re-soldered the connections....works like a charm now.

 

Dear all, I have the same problem as Mike in original post - just replaced DCCV, things improved little bit, but side & back vents are still blowing hot air. Checked RCCM module for defects - looks good (and multimeter says so aswell). Do you know where to find cable scheme from RCCM to DCCV? I think (and hope I'm right) there's problem in the cables...

What do you recommend to clean the temperature sensor?


Thank you, Jan.

 

Hi Jan, welcome to the forum. Here's my Proustian tome on climate control troubleshooting:

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

Watch out for tunnel vision, chasing one remote possibility (wiring?) while surrounded by other possible clues. Read through that guide first. Yeah, I know, it's a lot to digest. But it's very important to determine if you have no cooling or just inadequate cooling. Also turn down the temperature selection until the display shows LO. This puts the system in manual mode and bypasses many (not all) of the sensors. This is a big help for troubleshooting. Details at that link. Please post back here with your results.

 

Yes get and install the JTIS. It has all the stuff you are looking for and it's free on this site.

And be aware just checking the CCM or the RCCM with a meter is not enough. You might need to send the module in and have it checked properly.

Have you looked at this place?

- JaguarClimateControl.com
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