XK8 convertible, 1996 new purchase with non working air con.
Have had they system pressure checked and regassed but no luck. All fluid poured out from the pump.
Replacement pump fitted which is slightly different (lack of pressure switch) but confirmed by Jaguar specialist this is fine and done many times before as its controlled by other parts. System is regassed again (No leaks) but compressor pump will not kick in. Fitters worked with supplier Jag specialists to confirm pump works if bypassing or grounding some wiring and all worked.
Issue is now what may be wrong and how do I get it resolved without another large bill.
Any advice will be greatfully received
Thanks

 

I recently purchased a 06 XKR coupe, the air didn't really work. I used to be an AC Tech 25 years ago. When I put my guages on the car it gave the indication that the Thermostatic valve was stuck open or that the compressor wasn't doing much. Before biting the bullet and doing something serious I decided to drain the system and put a vacuum on it overnight. In the past I have found that really makes for a nice operating system. The next morning I put 1 lb 7 oz in it and it works like new. I haven't completely researched the Jag system but I believe that the ECM and the climate control module work together and one of them sends a PWM signal to the compressor which is a variable volume design. If my problem hadn't resolved my next step would have been to hook up a scope or multi meter with a pwm capability and probe the wires to the compressor and make sure that a PWM signal is being sent.

 

In my case I believe that the receiver drier was slightly restricted and vacuuming it down reduced the obstruction reducing the high side pressure and allowing a sufficient volume of refrigerant to get to the thermostatic expansion valve.

 

Your A/C system has a pressure switch that may not be working properly. I am attaching a few links that might help and one of them is to pull the codes on the A/C system.

Link http://jagrepair.com/images/AutoRepa...s/ACSystem.pdf

Link http://www.gusglikas.com/images/Auto...or%20Codes.pdf

 

Thanks for your messages and links.
Have had a look today and the system has got the following codes at present

11
22
23
24

The system as far as I am aware has a full charge for the air con system as I had a replacement air con pump fitted and it was regassed. No leaks have been seen to this day since.

 

I would clear the codes and install a jumper on the pressure switch to see if the compressor kicks in. If it does drain the system and replace the pressure switch, recharge the system and see what comes back.

Link See Fig 07.2 http://jagrepair.com/images/AutoRepa.../jagxk1997.pdf

 

Thanks for the reply Gus. I see the 'Refridgerant 4-Way Pressure Seitch in the middle, I assume the is the baby?
I'm no electrician so sorry to ask this but how would I install a jumper on the pressure switch? I assume you mean add a cable between 2 connectors?
If this is the case where would I find these points?

The garage that installed the replacement pump advised that the original was slightly different and had the pressure switch as a part on the pump. The new one doesn't but I'm told by the supplier (A jaguar specialist garage) that this one will work and it's controlled by a switch near the radiator. Any idea?
Just checking as I don't really want to blow something up by fiddling with something I'm not really sure about.
Thanks
Phil

 

I see you are looking at the other thread that has the information you need on the jumper.

 

Was doing a lot of searching online all over and came across that thread so joined in on that one in parallel. Yes they seem to have the details on there which is good.
Thanks Gus