i know it has something to do with pressure, but i don't know what pressure u need on low port,

so if u know what pressure u need to have on low pressure to work a/c fine or how many cans do i need to charge my a/c because it's getting cold way slow and then when i get out,outside feels lot colder than inside...

thanks in advance

 

Maikal, fo the freon system, it is a factor of two things. You have total weight of freon and also the low side pressure. The pressure should be between 30-40 psi with the A/C system on full blast (max fan, dialed as cold as you can get it to go). Lower pressure than that and the system will not function efficiently, above that, at high RPMs, you can stress the piping due to too much pressure (protected due to an over pressure switch built into the system).

As for the amount of freon, it should have 7 ounces of oil and 28 ounces of freon (R-134a only!!!!). THe oil I am sure about, but the amount of freon I am not 100% sure about. If you open the hood of your car, one of the stickers above the radiator tells you the exact amount of freon required. Please keep in mind that the total amount of freon needed is based on starting with an evacuated system. If you are low on freon (based on a low pressure reading), don't add 28 more ounces. This will lead to more problems than things it fixes.

 

thanks for replying on both of my posts

can u use regular air pressure gauge to check the pressure or u need something else

i added 1 bottle of 14 oz, but i didn't use whole bottle, i only used half bottle to approximate, so if pressure is low then i should go ahead and fill one can of it? will it be ok?

btw what pdt do u recomment?

thanks in advance

 

Maikal, to make a blanket statement that you should add the rest of the car of freon without knowing more info is a loaded question. This is where the freon gauge is going to be critical. As for using a tire pressure gauge in place of a freon gauge, that is not recommended. The two gauges are completely different and the big thing is that the freon gauge is a sealed unit and therefore will not allow freon to escape when in use as you need to leave the gauge installed for a long time to see where the system stabilizes. It will take a few minutes for the freon to reach an equilibrium inside of the cooling system.

As for the freon to use, like I mentioned before, as long as the freon has the oil inside of the can, use it. It is all the same chemical (or else it wouldn't be called R-134a). I can't say that I have heard of any difference between brands. Normally the price difference is based on the ease of adding the product and being able to monitor the pressure. So, what you spend is going to depend on what all you need to get.

 

Maikai_0011, the local Kmart, Walmart or one of the chain Auto Parts stores sell a kit with a couple of cans of freon pre-mixed with oil, a gauge/vale unit, and a DVD of instructions on how to top-off or refill the AC system.

It might be a blown seal - here's a great video on that: http://www.youtube.com/watch?v=HxJRSmIBjd4

NO - DON'T USE A REGULAR AIR GAUGE!!! You run a chance of burning your skin quite badly, blinding yourself, poisoning your self thru inhalation of the freon/oil mix, OR WORSE - DAMAGING THE PAINT ON YOUR JAG !!! (Oh my gawd - not the Jag!)

Just buy the kit, maybe less than $50, and follow the rather easy-to-understand instructions. At the very least, invest in a pair of safety goggles, and better yet add a full-face shield too.

Freon and oil have some rather nasty properties not many people realize. When it comes out of the can and it is still liquid, it is actually a BOILING liquid. It will give you (or your) car a rather nasty burn if you get enough on you.

Additionally, the oil is highly solvent and can be difficult to clean up.

The process is actually pretty straight-forward, and safe enough - just be exceedingly diligent. When you are done, if you have any juice left in the can, vent it out SLOWLY and then throw the kit away. Don't try to save the kit, they are (or should be) one-use kinds of tools.

If it works for a while and then craps out again, you got a shop job. If it doesn't work, you got a shop job. If it DOES work, you just saved yourself oodles of dough!

Good Luck!

 

thanks all for your help

i think i haven't charged it enough because when my car is moving fast i can really really cold air, but if i stop it switches back to room temperature air so i think i have to recharge it again

thanks

mike

 

maikal, are you sure your radiator fans are working properly? This is a sign that most people get when they have their radiator fans starting to go. At speed there is enough air flow to keep the A/C system functioning properly. But, at low speeds, the fans are not capable of pulling enough air to prevent the A/C system from getting warm. Just something to take a look at. If you need some checks to do, let me know.

 

thanks

so how do i able to check that?
should i turn on the a/c and see if fans works ? and i don't know where that fan is or air filter for a/c too?
in this situation what diagnostic would u run?


and i have another question but i will just start new thread,

thanks again

 

Maikal, to check the fans, put the A/C system into manual mode and put the dash fan on high and crank the temp down as low as it will go. This will put the system into max generation of cool air. Now, with the engine running, open the hood and stick your hand on top of the air filter box (dead center of the engine bay, has "JAGUAR" written on the top if it). Do you feel tons of air being blown by it or just a little bit of breeze? Tons of air, fans are working just fine. Little to no air, fans/controller are shot. The fans for the engine cooling-A/C system are located down in front of the engine, under the steel support that runs side to side at the very front of the car.

As for the A/C ventilation filter, with the hood open, up near the windshield, you will see a plastic cover the bridges the gap between the windshield and the hood. If you remove the 5 fasteners holding the front of this cover (cowl) down, on the passenger side you can lift it up some and that will expose the filter. I just bought a filter myself and it was $26 (Advance Auto Parts, filter 25600). To remove the fasteners, you simply need to lift the center of the fastener up about a 1/2" and then lift up on the whole fastener. No special tools are needed unless you need help getting the center lifted up. In that case, a small flat bladed screw driver works great for that by sliding it in and under the center post and then giving the screw driver a quarter twist.

 

i couldn't find the a/c filter, picture would help but don't worry about it i am going to dealer tomorrow anyway

and about the fan working, i put my hand on jaguar label underneath the hood, i couldn't be sure because of engine was running, but all fan that are there were running and moving as normal

well i go to dealer tomorrow and he will check the pressure and see if more freon needs to be filled then that will solve everything


thanks again

 

My air runs cool when I am on the freeway, but not on city streets where you stop and go. I changed out the filters. The freon pressure was actually high (I bought the car used 4 years ago). I put my hand on the engine filter (like THERMO mentioned earlier) and I did not feel a lot of air flow. The fans are turning, but it sounds like they are cycling (almost like they rev up and down). If the recirc on the air is off, there is very little air blowing. And it is not cool, basically room temperature. Do you think I need to replace my fan assembly or is it the controller (as mentioned in an earlier section)? And if the controller, is this the whole A/C Unit Contoller?

 

I was just about to start a new thread on this. My fan doesnt work at all as i never here it kick on. Since it started to get warmer I noticed the engine starts to overheat if I idle in traffic over a period but it cools back down once I start to move. The same applies to my ac it runs cool when am moving but runs hot when am idling. I read in the JTIS about how to test whether its the fan control module or the fan motors thats out. Thermo and the more technical people on this forum I need help in layman's description as to how I can find out whether its the fuses, fan control module or the fan motors themselves is the problem and what tools I need for that. Help with this will be very much appreciated

 

kojo, first do the idiot test of the car. What you need to do is to open the hood of the car. Next start the car (with the motor cold) and the A/C off. The fans should not kick on. Now, turn on the A/C in manual mode and set the fan to the maximum speed and the temperature as low as it will go. This will force the fans to turn on at max speed. You will know they are at max speed as you will feel a significant amount of air moving around in the engine bay. If you are getting a nice gentle breeze or no air movement at all, then you have a problem with the fans. You should also be able to hear the fans running at this point.

As for testing the fans. First, turn off the motor. Next remove fuse F8. This will ensure that the fans will not start on their own. Next, unplug the connector on the fan control module (located near the battery box) on the fan shroud. Now, look at the plug that you just removed from the control module. You will need to make 2 jumper wires to short 2 pins together. First, located the following wires:

Brown wire with a green stripe
black wire
orange wire with a green stripe
yellow wire with a green stripe

The first jumper wire will go between the black wire and the yellow wire with a green stripe. The second jumper wire will go between the brown wire with a green stripe and the orange wire with a green stripe. Now, verifying that Fuse F8 is good, install fuse F8. Did the driver's side fan turn on? If no, verify that you have 12 VDC on the brown wire. If you have 12 VDC, then you have a bad fan. If the fan turned on, then you know that fuse F8 is good and the fan is good.

Now, remove fuse F8. Remove both of the jumper wires. Now we are going to install the jumpers between the black wire and the green wire and the second jumper between the brown wire with a green stripe and the red wire. Reinstall fuse F8. Did the fan turn on? If no, you have a bad fan. If yes, then this confirms that the fan control module is toast and you need a new control module.

While this doesn't test the signal wire coming from the ECU to the fan controller, if you had issues there, you would be getting error codes as the ECU would most likely be experiencing a multitude of problems.

Hope this helps.

 

Thanx thermo i will give it a whirl today

 

Ok I think its the fans. It doesnt kick on at all with ac cranked up at a low temperature.

 

When you say fans, are you saying that it is something from the controller on out or did you do all of the testing that I said. Just because the fans don't turn on when you turned on the A/C, you can be replacing a lot more parts than you need to (ie, controller and the fans vice only replacing the controller which is the most likely failed component). Granted, it can be something as simple as the fuse having given up from years of use. Then it would be a simple $2 fix.

 

Yeah i kinda realised that didnt exclude the fuse and the fan control module. I will be doing the rest of the checks this weekend so i know for sure.

 

I changed the fan control module and now they r working. R u still investigating the issues with these modules thermo? I now have 2 non-functional modules if u r interested thermo

 

Kojo, yes, I am still looking at getting my hands on some failed fan modules. If you have them, send them my way. I will cover the S&H for the modules. Send me a PM and we will get things all straightened out.

 

Thermo, as a new member to the forums I'm finding your are quite knowledgeable and want to thank you for helping so many of us.

As a guy try to save a few bucks I have been reading this thread trying to determine why my AC isn’t blowing cold air. Initially I was thinking the Freon needed to be recharged. I was going to pick-up a kit at AutoZone next week and give it a try. But after reading more and doing what you have suggested about feeling for movement of air when the AC is on manual, at lowest temp and running the AC fan on high. I believe my issue is may have something to do with the cooling fans, as I feel no air movement when I stand over the engine and feel for air movement.

So here is my question, I believe I’ve identified where the control module connector is located and would like to test as you have suggested using a “jumper wires’, but what is the secret to disconnecting the connector? I can reach it, but I don’t want to just yank away. Does it need to be turned or is there a clip?

I know it sound like a foolish question, but I would rather ask and risk ridicule, then make the problem worse.

Thanks again and thank you to others that are sharing.