After 6 months of ownership, the car finally throws up a problem!


The Air-Con / Climate control is stuck on FULL BLAST, it's like a bloody freezer in there!


The panel reads "LO", the A/C light is on and the DEFrost light is on.
None of the buttons on the climate panel do anything, no on or off or up/down, just stuck with maximum cold flowing out.


I've disconnected the battery in the hope it would reset something but no joy.


All other controls work normally.


Anyone have any ideas?


Cheers, Jay.

 

Try looking for codes on the PDU, when you exit (the interegation procedure) it defaults to 75F or the equivalent centigrade or it does on mine:

To check for error codes in the Climate Control System with the internal diagnostics via the ‘Panel
Codes’

1. Ignition off - hold down AUTO and RECIRCULATION buttons and
switch on the ignition

2. press AUTO button - if ZERO shows, there's no stored
error codes

3. Press the RECIRCULATED AIR button to start diagnostic, sequence will start to test system.

4. press FACE button repeatedly to scroll through stored
fault codes

5. press FACE and HEATED REAR WINDOW buttons together to
clear a fault code.

6. repeat step 4 if there's more than one code

7. press FAN button to exit Interrogation Procedure

 

Thanks for the suggestion, but as I said, none of the buttons work so checking for codes isn't possible!

 

The DTCs can be obtained with PDU (Portable Diagnostic Unit) or WDS (Worldwide Diagnostic System) as long as the communication network is intact and the module communication capability has not failed.

Finding someone with either diagnostic computer might be your main problem. They are BOTH terribly out of date (dinosaurs).

You might 'borrow' a known-good' climate control unit from someone to see if the fault follows the car or the climate control panel. If the replacement does the same thing, then the fault is with the car!!!

bob

 

Is the actual control unit self-contained within the switch panel or is there a related ECU for the climate?

Finding replacements shouldn't be hard (or expensive).

Thanks!

 

I've found a control Unit cheap and ordered it.

I've also found there's an ECU for the climate, can anyone tell me it's location on the car?

Thanks!

 

JEPC only lists the climate control panel (LJA7690BB).
No other controls for the AC except if you have HEATER CONTROL PANEL (with or without heated windscreen)

I have never seen an X300 without AC (heat only) in U.S. configured cars.

bob

 

Jay,

The Air Conditioning Control Module is mounted on the right side of the Climate Control Unit, the assembly in the center console behind the climate control panel and radio. I think you can access the electrical connectors by removing the right hand knee bolster, but for full access you may need to remove the glove box. Here's the illustration of the control module from pdf page 22 of the '95 XJ Electrical Guide:




You can download the Electrical Guide at the link below courtesy of forum member Gus (take a moment to send Gus a note of thanks):

http://www.jagrepair.com/images/Auto.../jagxj1995.pdf

See pdf pages 122 for the climate control system component identifications & locations and pdf page 123 for the electrical schematic.

Off the top of my head, it might be worth checking the electrical connectors at the bottom end of the A/C Control Module for corrosion or signs of water ingress. If the drains below the evaporator have become clogged, condensed water can pool and slosh over the edges onto the control module when you go around corners.

Cheers,

Don

 

Thanks Don, that's VERY helpful. I have just recently started getting wet feet when driving and just this afternoon worked out it was coming from the air box vents in the footwells.

I'll try and find the drains and check the connections for water ingress.

Cheers! Jay.

 

Turns out this was just the control panel. £15 replacement from eBay. Job done.

Thanks for the assistance.