My Jag was blowing hot air so I replaced the Climate control valve. After the installation, It was running rough and started to overheat, so I figured I had placed the lines in reverse order so I switched the lines up again now it’s running regular but it’s still overheat so I’m still not sure whether the lines are in reverse order or correct. But the car is overheating now.

 

Probably the bad valve damaged the module as so often happens.

 

Hi
its usually air locks, if you drain any of the coolant system
it can take some getting out, there is a procedure to de-air the system

 

Three lines on the valve, right? One larger supply input, and two smaller outlets to the heater core, IIRC. Due to the size difference, I think you could only swap the two smaller outlet hoses. The only effect you'd see is the driver's side of the panel controlling the passenger side, and visa versa. Connecting those hoses backwards would have zero effect on the engine temperature.

As previously mentioned, there is a bleed procedure to get air out of the lines. If not followed, this can cause the engine to overheat. Do not drive the car until this is corrected.

The cooling system is self-bleeding to some extent, but it takes several heat/cool cycles and topping off the coolant level each time. You must keep a close eye on coolant temperature to avoid any risk of overheating. Don't just hop in and drive away. If there is any question, follow the official bleed procedure instead.

 

You probably know this already, however, it is very important not to mix the long life anti-freeze with other types.
If you do the mix can congeal in the system causing overheating.

 

Do you have a V6 or V8? You didn't specify, but the arrangement is similar for both. Under the "S-Type Technical Guide" section, open the "S-Type 2003 Update":

JagRepair.com - Jaguar Repair Information Resource

Scroll down to page page 52 for the V6 or 54 for the V8. Here's the diagram for the V6. In both cases, the DCCV is item #1:



As previously suspected, if you were to switch the two smaller outlet lines, the only effect is the buttons on the control panel would adjust the opposite side. Zero effect on engine cooling. If you managed to stop all flow to the heater core, once again that would be zero effect on engine cooling because it's the same as requesting max cold air in the cabin, which shuts off all coolant flow to the heater core. If the hoses were connected such that coolant flowed continuously to the heater core, this would be the same as requesting max heat, also a normal condition.

When bleeding air from the system, don't forget to request maximum heat. This moves coolant through the heater core and helps expel any air there.