I have a 2014 XJL that has developed an a/c problem that I've never encountered before. Although cold air always blows out of the two vents (middle dash & far left) for the driver, on occasion, only warm air blows out of the vents on the passenger side of the vehicle. This is an intermittent problem, although it is happening more often than not. I should also note that this problem occurs regardless of whether the a/c control is set for manual fan speed or automatic temperature control, and it occurs even when both left and right controls are set at the same temp and/or the coldest setting. Can someone explain to me what is or may be causing this to occur?

 

If you have the A?C-heat set to manual and it is changing temps on you, then this confirms a mechanical issue with one of the dampers inside the dash. If you have the temp set on automatic, then it can possibly be the system doing what it should. Not to ask a silly question, but is someone riding around with one of the windows or sunroof cracked open? This could possibly affect the temp sensor for one side of the car and this would cause the damper to shift and change the temp coming out of the vents. Granted, this same sort of condition could be simply caused by the temp sensor on the passenger side having an issue, making the computer think that the passenger side is hotter than what it really is. But ,this would only be true if the temp change only occurs in the auto mode. So, this kinda points back to one of your dampers is either not being held in place by the actuator or the blade inside the dash has come loose and it is allowing for air to go where it shouldn't.

 

If you're low on Freon charge, the passenger side starts blowing warm Before the driver side. Not sure why or how, but it does. Happened to me with my X5, the driver side was ice cold, passenger was much warmer. After a while, the drivers side stopped blowing cold to. Got it fully charged and both blew ice cold again for a few months. Then the passenger side once again started blowing warmer for a few months till the drivers finally went warm again too. Now I just charge it myself with a $40.00 pep boys charge can every season and it keeps it ice cold on both sides.

 

To throw another problem into the bag - on RHD cars cold on the right hand side, hot on the left is also the symptom that the heater core in the dash is starting to block up and needs back-flushing or replacing. It sits after the AC evaporator and catches all the sediment, corrosion and other contaminants in the coolant circuit eventually blocking off the far side entirely so it never heats up.

It's the wrong side blowing cold for you unless the heater core is reversed on LHD cars. Low pressure in the evaporator would logically have a similar effect as phillyS1 mentions if it removes more heat from the inlet side and less from the far side.

Always start with the simplest cause first - get the car connected to diagnostics software and check the mixer flaps are working, and the refrigerant pressure. If they check out ok then you can pop the glove box out to access the core. It's a knuckle scraper, but you can remove the pipes keeping a closed system and not lose too much coolant (bottom first and cap the core, then top and slide it out). You can connect it to a garden hose to backflush it, or just swap it out (it was a £50 part when I last bought one).

 

I apologize for the delay in my getting back to this thread. My 90-year-old father was hospitalized shortly after I posted, so obviously my a/c problem (and this thread) took a backseat to dealing with that issue. (He's back home and doing fine now, btw.)

In any event, I wanted to thank you all for posting your suggestions. I took the car to the dealership last Thursday and it turned out that the problem was a broken a/c pipe which was leaking Freon. The service department ordered the part and I had my car back Friday afternoon.

I do have something embarrassing to add, by the way. When the service advisor told me what the problem was, I asked him how much it was going to cost for the part and labor. He informed me that there wouldn't be any cost since the car was still under warranty. I bought this car new in October 2014 and for the entire time that I've owned it, I incorrectly thought the warranty was 3 years/50k miles rather than 4 years/50k. I have been operating under the assumption that my car has been out of warranty for the past 6 months, when in fact, I have almost 6 months left, lol.

 

Thanks for posting the successful outcome. Good to hear both car and father are back home and well.

I've added 'RESOLVED' to your thread title.

Graham

 

1 of the rear vents is not blowing air. anyone experience this?
turning up the fan speed does not help.

 

Hey jagmt,

I've tried using the A/C Pro refrigerant canister. But it didn't connect to the port under the hood. How did you apply the canister?

 

There are 2 ports, a high pressure and a low pressure. They are designed so the fill canisters will not fit on the high pressure port. Make sure you use the low pressure one.

 

JagGate,
Thanks for the quick reply. finding the low pressure port has been the problem for me. I see a port under the hood on the driver side. The canister seems to fit but does not active the canister. I saw a video that shows a port under the right wheel but I can't get to it. Is the port under the tire well the low port?

 

This is my issue as well, phillyS1. Took it to get freon added last summer, but the problem is back this summer. Too hot to drive without a/c and too cheap to take it in for this simple problem (again). Only 1 shop in my area will dare touch a Jag, so they really take advantage of the pricing. Can you give a step-by-step on how to do this, please? Thanks in advance!

 

Jackson411, go to your local auto parts store and get yourself a can of R-134a freon. Make sure to get one with the gauge on top and the 12" hose coming off of it. Before buying the freon, look under the hood to confirm that your car does take R-134a freon. Putting in the wrong type of freon can do some really nasty things to a vehicle.

Now, locate the low side port (drivers side for US cars, behind the headlight). You will find 2 ports there. The can of freon will only fit on to one of the ports. The other one is too big to fit. If it is around 75F (may need to do this in the morning) and the engine is cold, you can connect up the can to the port and you should see the gauge on the can jump up to around 60-80 psi. If you are getting something less than that, then you have lost some freon. This is where while it may be more expensive, getting the leak fixed is going to save you from a really expensive fix later on. This is especially true if it is down near 0 psi.

Now, what you are going to do is start the engine and turn the dash fan on to maximum speed and dial the temp control to the lowest temp it will go to. Following the directions on the can, depress the trigger and add enough freon to bring the dial up to the green band on the dial (should be between 15 and 30 psig, this is the recommended pressure called out in the Jag repair manual). Yes, the running pressure on the low port is going to be lower than when it is static.

Following the instructions on the can is key. I say this because the can of freon also contains an oil that lubricates the compressor (R-134a is not a good lubricant in itself). So, holding the can the wrong way and/or not shaking it properly can affect how much freon and oil gets put in the system.

Also of note, this is just getting you close to where you need to be. For this to be done properly, you should have the system evacuated and then have the proper amount of freon (by weight) added to the system. While pressure gets you close, it is not perfect.

Also of note, when making and breaking the connection from the can, keep your hands as clear of the area as you can. Getting freon on your skin can lead to a burn (well, frostbite, but it is the same feeling). It can happen extremely quick. A little puff is no big deal. Getting an ounce or two on your skin is going to be a memorable experience.

 

Thermo, I'd buy you a drink tonight if I could! With your help, I was able to fix the problem. Noticed the cap on the low pressure valve was not put back on after last year's trip to the Jag Doctor, so I'm thinking that could be the reason for the slow leak. Blowing nice and cold now, which is a welcomed change in this 100 degree weather. Appreciate your help very much!

Cheers,
RJ

 

 

Yes, that is where the low pressure port was on mine! Not where I thought it would be at all, but that was it.

 

Thanks so much. I saw videos that showed the port being in the right wheel well. I hope this will help someone else because I couldn't find an answer on our trusty forum.

 

Fixed for under $40. Thanks to all for providing this information.