Neither heat or a/c was working; so we recently changed:

1. Ambient temp sensor;
2. Heater control valve;
3. Climate control switch;

and flushed the cooling system including the heater core.

Now, ambient temp sensor is reading the correct outside temp, and the a/c works fine.

But the heat still does not and no codes.

Does anyone have a clue???

Many thanks.

Ken.

 

Use the search function as this has been covered countless times.

Most likely caused by failure of the DCCV (Dual Climate Control Valve).

Read through this thread that Karl painstakingly researched and documented:

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

 

Ditto. Treat Karl’s post as the Bible, it details the S Type HVAC system better than the engineer who designed the thing.

 

Um, you must be aware it's considered poor form on the forum to compliment me like that. Makes my head swell up and then I can't fit through a normal doorway. I'm trapped inside the house until my wife gets home to bring me back down to size. Fortunately, she keeps a handy list of my faults.

 

Hi Ken,

What is the "climate control switch"? Do you mean the control panel, or something else?

Please work through the troubleshooting guide, linked in an earlier message. Specifically, work through post #2 to test the Dual Climate Control Valve (DCCV). This valve has a high failure rate so there's no guarantee the new one is good. The module has two valves, each spring-loaded to the open (maximum heating) position. The logic is to provide heat to the defroster for safety in case of an electrical failure. No heat is obviously the opposite, so I'm not sure what's happening.

Also work through post #6 in the guide, which covers low or no heat. It has a few specific things to check, such as coolant temperature. If the engine is running cool, you won't feel much (if any heat) Don't rely on the dash gauge to accurately indicate coolant temp, as from approximately 180-230F, the needle remains centered. I recommend using an infrared thermometer (very inexpensive nowadays) to measure the temperature at the radiator inlet (upper hose).

How much have you driven the car since replacing the DCCV? There's an elaborate procedure to bleed air from the cooling system. The system is self-bleeding to some extent, but that requires several drive cycles and you must be very careful not to let the engine get hot. You can also expect to top off the coolant for several cycles until the self-bleed is complete. Also, at idle the heater performance is marginal at best, due to low coolant flow. V8 models have an auxiliary coolant pump to help. Have you checked its operation? Put all that together, and if you haven't driven the car much after repairs, you may not have much heat at first.

 

I’m sorry man, I can’t help myself. I owe my orgasmic ice cold ac to you.