My air cond. was not putting out what I was used to as far as cooling. Temp here has been in the 90's. I bought a kit with gauge to do a recharge.

It only took about 6-7oz approx. I may have held the can upside down when charging, hopefully I did not screw something up. Low pressure side is showing approx. 35lbs. Cooling did improve.

On the way home last night I heard a loud wooshing sound that I thought was the compressor but turned out to be the fans running at high speed which I have never heard before. Getting home and turning off the ac. the low speed fans did not come on when I restarted the engine.

This morning I checked the fan fuses first and they were ok, started the engine and fans came on low speed as normal. I put the low pressure guage on the port and there was a slow fluctuation at first between 20-40lbs when the compressor would click off and the cycle would start again. After a while it stabilized at about 28 lbs.

When I turn the ac. off the low pressure will climb to approx. 50-55 lbs. is this normal? What would make the fans run at high speed but not at low speed last night?

Are these recharge kits a good idea or should one pay a professional to service the air conditioning?
Vehicle is a 1996 XJ6

 

The fan has separate triggers from coolant temperature and a/c head pressure. A TSB modification deleted the fan low-speed switch from the a/c circuit, meaning the fans run on "low speed" or in series at all times the key is on. Apparently, your car does not have this modification.

I forget the values, but they can be found either in the service documentation available for free download or with a diligent search, here. For your car, sans TSB modification, with a/c off, your fans will come on low speed when radiator tank temp reaches 87 deg C, I believe. I don't recall the temp, but likely somewhere at or barely above the 92C T-stat point, the rad top tank temp will cause a switch to "Hi Speed" or parallel operation.

With a/c on, when head pressure (Hi side) reaches a certain point, a switch closes and turns the fans on low. (This switch was prone to fail in the "stuck open" position and is the genesis of the aforementioned TSB and subsequent deletion entirely on later-builds. As head pressure continues to climb, another switch on the hi-side line closes and commands hi-speed fan operation.

Ok...so far we've played a little piano ditty with the left hand, and another with the right. (This next step is where I lost it in piano training as a child) How do they work together? Depends somewhat on the ambient conditions and your driving, but generally speaking, the a/c will command the fans to low, then hi, before radiator tank temp ever gets to the low-speed trigger. When you have a failing low-speed a/c switch, the fans go from OFF to HI due to the hi-pressure/hi speed switch. This, more often than not, blows both 30A fan fuses in the left hand engine bay fuse box and results in "No Fan." as in at all, ever.

FWIW, I seem to recall with my car shut off, on a 90F day, both hi and low side pressures are equal, and somewhere around 100 psi. 50-55 psi seems a bit low if it stabilizes there with the system off. When you speak of a kit....I guess you mean a can with a hose and one gauge? You have not hooked a manifold & gauge set up where you have both hi and low side pressures available to read?

 

The X300 A/C system has a self test ( Jaguar TSB 14 - 10 ) built in that may give you some information with the resulting codes . But it does not confirm proper radiator fan operation .See the 2 following Youtube videos .

https://www.youtube.com/watch?v=tRlf...<br /> <br />

Some of the newer Freon recharging cans at the auto parts store have color changing plastic clips ( mood rings ) that you place in the vent to confirm proper cooling temps with the Carnot Thermodynamic Cycle it is a function of the Freon pressure so no pressure gauges are required . I would suggest purchasing one of these cans , borrowing the clips , and returning the can with clips after testing .

Avalanche R-134a refrigerant with hose and smart clips AVL132 - Read Reviews on Avalanche #AVL132

Upside down can procedure is the proper way to use the cans for there is a lubricating oil along with the Freon in the can . Over the years a new dryer ( located above the radiator ) may be needed as they degrade and release the drying particals into the Freon lines clogging the very hard to get to expansion valve making the A/C system useless . As a preventive measure I plan on replacing mine and flushing the system before it clogs the expansion valve .

4Seasons/Everco A/C Receiver Drier 33494 - Read Reviews on 4Seasons/Everco #33494

26 dollars US but require a change of Freon which can be found cheaply on Ebay . Environmentally the Freon should be evacuated or removed by a shop to not vented to the atmosphere . If you want peace of mind that both fans and your control relay module ( located under the car below the engine air filter ) works you can just insert a paper clip in the coolant temp switch connector and the A/C pressure switch connector and watch the fans run without the engine running . Ref X300 Wiring Schematic figure 7.1 . 5 minute test . Low current/power circuit so no arcing or damage concern . Just verified this test with Lady P . With the key in the on not start position the coolant temp switch is located an the radiator very lower left side . Contact the sockets for wire White Blue to Black will give you both fans , White to Black will give you the one left side . On the A/C switch it is the 4 wire connector located on the A/C lines on the aft firewall bulkhead . Contact the White Blue with either of the Black and you will get both fans . This test will only verify the relay module and the fan motors and not the switches themselves . You can clean and put some bulb grease on the connector for the under car relay module for I found the other connectors in the area corroded . What I found on mine was the relay control module ( by cutting it open with a saw ) was full of water and corroded / bad . You can save some big money if you have to replace the Denso 10PA17C compressor with the following kit :

Denso 10PA-Series Compressors

See the following Youtube videos : Part 1 and 2


You can take the removed compressor to a shop and they may remove the nut with an impact gun . The clutch bearing is somewhere on there site . JAGUAR AC Compressor DENSO 10PA17C Clutch Bearing NSK 30BD5222DUM6 30mm ID x 52mm OD x 22mm Thick.

The compressor clutch may ( ? ) be able to remove on car without removing the compressor .

See Youtube video :

The compressor belt tensioner bearing may be bound up , damaging the belt, and squalling the bearing surface . Gates # ( ? ) .

Best Idler Pulley Parts for Cars, Trucks & SUVs

To get the tensioner off the long adjustment screw will most likely be frozen with rust so I removed the whole assembly and put it on a bench . Using a wire brush , a heat gun , some spray , and a large pair of vice grips ( use before the pounded on socket method before you round off the needed points of the 4 sides into a socket ) it will eventually free up the long adjustment threads so it can be adjusted . Run the treads up and down several times to clean out all the rust . As an emergency you could just " roll " on the belt with the before repaired frozen adjuster threads . Pound on a properly sized 6 or 12 point socket tool on the end of the 4 sided square and leave it on there for easier in service use on the side of the road and put some heavy grease , not spray , on the long threads .

Unfinished Post and will edit later .

Hope this helps .

Thanks , Parker

 

There should be an arrow on the can that points to the position of the can while charging.

The can has two options,charging with the can upside down will charge with liquid and is extremely dangerous,if you are not useing gauges and throttling the liquid in then you can burn the compressor out quick.

Liquid freon is charged on the high side or smallest of the two lines only with the compressor off,the gas or vapor charge which is charged through the larger of the two lines and with the can in the upright position.