The a/c on my '05 s-type is blowing warm air on one side and i'm told the blend door is stuck and has to be replaced. Does anyone know where it is located on the car?

 

I'll hazard a wild guess whoever told you that has never worked on an S-Type. There is no blend door for temperature control. The door actuators control the air source (fresh or recirc) and exit point (floor, dash, or defrost), but that's it. Temperature for each side is controlled by adjusting the coolant flow through a split heater core.

More details than you probably care to know are here:

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


Run the tests in post #2 to see if your DCCV is sticking open on one side. That's the valve which controls coolant flow to each side of the heater core