So I just installed a brand new AC system (new compressor, evap and drier) on a 2000 S Type. Unfortunately when it is running I get a strong mix of heat and ice cold air coming out of vents.

I just had a new DCCV installed a few months ago, so I doubt that is the issue unless it was installed incorrectly. I have been digging around the threads here quite a bit and it looks like the remaining culprits include:

1. Aux cooling pump
2. Climate control unit
3. Evap sensor
4. AC control module

Where to start? The exact symptoms are:

* Cold and Hot air mixed in each vent (not specific to any vent)
* The issue gets worse at speed, better at idle but heat always present
* Turning recirculate on or off does not change anything
* If I turn the AC to defrost and/or floor, its much colder

Thoughts before I just throw a dart?

 

Almost 100 views and not one single opinion? The forums have failed me, back to my weak google-fu

 

You have a unique problem. That may explain the lack of responses....

My guess is that if your DCCV and A/C system are working properly, the next culprit would be the Climate Control Module. But that is strictly a guess....

If you have not communicated with the guys at jaguarclimatecontrol.com yet, you should. They are very knowledgeable and can point you in the right direction....

 

I found a used CCM on ebay for under 30 bucks shipped, so we will start there. Thank you.

 

Sounds like the flaps not working or one side is OK and the other duff. Can be wiring related. Run the checks on climatecontrol.com and you will have your answer

 

When I had that problem along with replacing the valve, I took the ccm apart and found four copper traces burn't on the circuit board. I took some fine insulated wire and ran it to the solder joints that were burnt away and everything works great.

 

Hello all new member here, I have a similar problem with my 04 stype base 4.2 air blows fine on passenger side . But floor rear and driver side blow hot. The floor also has a lot of heat coming from it even when the climate control is off. I had the dccv replaced already. I pulled the ccm didn't see any burns on the circuit board. Also blend door on passenger is still intact. Any suggestions?

 

Wow, 9yr old thread.

See Karl's one about troubleshooting.

 

Start with post #2 in this troubleshooting guide:

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

No guarantee your new parts are good, so don't fall into that trap.

 

So crazy enough I had a issue similarly and couldn't find out why my driver side was letting the hot water come through when I gave it a little gas. I also did a ac compressor and drier. I'd have ice cold air until I moved. Well I bought a new dccv not checking my already new one I installed over winter for not having heat. But I found the wires up top of rad. And I checked voltage. Well. My driver side had close voltage just every now and then and it would open up. My passenger side worked fine. So until I can figure it out I just joined the pass and drive wires together to function as 1. And boom I have heat when I want and cold when I want. It dosent allow left to right but for me and family I don't really care so it's ok for me at least until I can figure out the issue. Try maybe sending the voltage needed to close to them wires and see if that fixes it.

 

Might be a bad sensor telling the system the drivers side is TOO COLD so it opens up the heater valve to allow coolant into your heater core.

When this happens do you have the temperature set on low? Or do you have it set to a specific temperature?

Set it to low and see if it happens

have you taken your climate control module out And opened it up to see if the traces have been melted and replaced with the resettable fuses that I have mentioned in another post?

That heater control valve is dependent on a multitude Of different sensor inputs and if you’ve got one that’s faulty it could be telling the climate control module to let some heat in on the driver side

 

Hey there. Yes I have pulled my control out and it looks great nothing burned and the temp is set to lo.. I've tried to search and search. I don't know what sensor to even look for that would cause that on my driver's side only. I'm also getting a issue where my ac clutch likes to just stop grabbing someday. New compressor. So I dont know.

 

So the problem of dealing with these modern auto air-conditioning systems is that you need a lot of data in order to find out where the problem is. For instance you need to know what the outside temperature is. What the vent temperature is. What is the high and low refrigerant pressure. Are they changing as the problem occurs or are they steady? What is the voltage going to the compressor clutch is the relay that operates the compressor clutch faulty what is it actually being commanded start and stop the clutch? What is the sensor reading for the high-pressure switch? For the solar sensor? For the external air temperature? For the evaporator coil temperature? For the interior car temperature sensor? What is the resistance of each DC CV coil? What DTC faults are you recording? Are your radiator fans always turning? Are they in low or high speed?

I’ve had very weird problems with my Jaguar. for instance I had a terminal in the fuse box for the compressor clutch relay that had been pushed down into the fuse box so it wasn’t making contact with the relay terminal. I’ve had corrosion on connectors which caused high resistance or low current conditions and open circuits. I’ve had wires that were broken but the insulation was still intact so it looked fine but depending on which bump I hit it made contact or didn’t.

But as I said it sounds like something is commanding that heater valve to let in coolant so everything that might be an input to determine the state of the DC CV needs to be looked at