This has probably been answered in the past, but I missed it.

When I select Defrost on the Climate Control panel, the A/C button light also comes on along with the Defrost button light and even when I set the temp to "HI" on the climate control, I cannot get warm air to blow out onto the windshield, only cold air. BTW.. I also tried to get the floor heat to work - again cold air only but at least I can turn off the AC button when floor heat is selected.

Is there a solenoid/valve that has to swap over/open to get hot coolant to flow through the heater/vent coils to bring heat into the cabin, be it defroster or floor heat? I think that I might have read somewhere that there was a solenoid that is normally "closed" - preventing warm coolant from entering and had to swap to "open" to bring heat into the cabin. If there is such a solenoid/valve does anyone know where it might be located?

Thanks in advance...

 

It sounds like your temperature blend door is not functioning properly.
Check post #8 in this thread for more info.
https://www.jaguarforums.com/forum/x...-vents-107254/

 

Panama: Your post has several questions.

#1) There is no valve in our X-Types to control coolant flow thru the heater core. Temperature is controled with air dampers, also called flaps that direct air thru or around the heater core.

#2) You are correct - when the Defrost button is on, the A/C is also on all the time. This is a "feature", not a problem! The A/C dehumidifies the air, because dry air more quickly removes (actually evaporates) condensate fog from inside the windshield. If you wish to blow air at the windshield without turning on the A/C, instead of the Defrost button, use the button above the #3 button to blow air at the windshield and your feet.

#3) With the engine warmed up to normal operating temperature (and make sure you have a full reservoir of coolant!), you should be able to blow warm, dry air at your windshield by turning the Defroster button on and setting the temperature high. Granted, the air may be warm, not hot because the A/C is on. But it should be warm, not cold because the air is also flowing thru the hot heater core. If the air is cold, you may want to try resetting your stepper motors, which open and close the air dampers. This thread describes that procedure:

https://www.jaguarforums.com/forum/x...hot-air-95548/

 

Would it be reasonable to assume that actuator #4 (Temperature blend door actuator) is malfunctioning? - see attached Adobe file/drawing

I all areas receive good air flow, just no hot air.

 

I assume that is the problem. I have never had this problem, but I would disconnect the actuator and manually rotate the damper and see if that gives you heat. You could also try changing the temp setting to see if the actuator is turning. Take care though. It appears that it is possible to drop the damper into the heater and then you have real problems - see link.
https://www.jaguarforums.com/forum/x...d-door-111458/

 

Panama: Thermo describes in this thread how to access the stepper motors by removing the glove box, and how to determine if your flappers are stuck vs. broken.

https://www.jaguarforums.com/forum/x...removal-85196/


thegreytribe describes in this thread how to confirm the flaps are not broken, then how to diagnosed and fixed misalignment between the stepper motor and flap:

https://www.jaguarforums.com/forum/x...system-117663/

Attached is a picture of the stepper motors - easier to visualize here vs. peering thru the glove box hole and under the dash.

 

Thanks for the photo!! - always better to see what to expect than imagine and guess. - Looks like my weekend is planned!!

Thanks again to all for the responses - Will update when I know more.

 

So I gained access to stepping motors and removed the actuator from the Temp Blend door.

(1) I raised and lowered the desired temp on the climate control console while the actuator was removed - no rotation/movement of the actuator shaft.

Bad actuator motor?

(2) I manually changed door position with a screwdriver - the door rotates approx 1/4 turn from stop to stop - no change in air temp coming out of vents.

No hot coolant flow to heater core?




(3) Okay - after getting no temp change in the cabin after manually opening the temperature blend door, I checked the heater hoses. The hoses at the engine block were both nice and warm, however the return hose from the heater core where it "T's" into the hose between the coolant reservoir and engine block is still ice cold. So guessing now have a blockage somewhere in the heater core itself.

So apparent fixes needing to be done are (1) replaced actuator and (2) flush heater core. Replacing the actuator is easy, just get the part off e-bay. Anyone have a good method to flush heater core? Will standard water hose pressure be enough to clear blockage I wonder....

 

Went back and did a full temp cycle "Hi-Lo-Hi" on climate control console with actuator still removed and found out that the actuator did most of its movement around the "Lo" setting - specifically the shaft turned mostly just to get the door open/closed. The actuator made more small movements from around 76-"Hi" and back down from "Hi" to around 76 again. It is around 70 degrees here now and movement may be significantly different if it was around 32 degrees

So the actuator is working and the blend door is likely moving as expected, but since I believe there is no hot coolant in the heater core - gonna have to get the core flushed to get hot coolant flowing again so I can verify blend door is opening properly.

Just thought I would share my experiences in case someone else should happen to be similarly afflicted

 

Pamana: You're making good progress. Keep going.

Does hot air blow from any vents (windshield, passengers or feet) under these conditions:
1) Coolant reservoir is full
2) Engine warmed up to normal operating temperature, i.e., ~midway on the temperature gauge
3) A/C off
4) Fan on
5) Temperature control door manually turned fully to either stop?

If 'yes', hot coolant is circulating thru the heater core.

If 'no', the next step is to figure out what's keeping hot coolant from circulating thru the heater core.

In your 3rd picture, the one with the hoses labeled "hot" & "cold", the hose closest to the battery labeled "hot" supplies hot coolant to the heater core. The hose labeled "cold" is the return line from the heater core. If hot water is flowing into the heater core and cooler water is returning from it, then the temperature drop of the coolant should result in a temperature increase of the air blowing into the passenger compartment.

Alternately, water is not flowing to/from the heater core due to a blockage. Someone whose done this before may have a better idea, but here's a suggestion: Disconnect the supply and return lines to/from the heater core and try blowing air or water thru it.

 

Clapp, Thanks for all of your time and effort - it is REALLY appreciated!! I was doing exactly what you suggested as you were responding.

I LOVE a happy ending.... don't you??

I took the heater hoses off and flushed what looked to be about 1 lb (a small exaggeration - but not far) of gunk out of the heater core using a water hose. I alternately flushed each direction until I got no more gunk (took about 4 times each direction. Reconnected the hoses, refilled the coolant reservoir, started her up - let her get to temp and lo-and-behold we have heat in the cabin again (mama is now happy - so everyone can now be happy )