Climate Control System MK3
 

My 89 convert climate control system sort of works.
Plan is to try and get it running properly - with some help from this great forum.

When I purchased this car the PO had spent 4K NZ ($2600 USD) to get it working, so it heats and cools as expected.
But on the long drive home the aircon was blowing cold on to my foot which got real cold.

I have done lots of reading and have done the following tests.
Looks like the system will not turn on the centre vent, I read Warrens blog and saw that he need to fix a board and fix the centre flap.
Jaguar XJS Restoration : XJS Delanair Mk3 Repair
Where should I start?

https://cimg4.ibsrv.net/gimg/www.jag...27dc585a41.jpg


Engine at running temp
Both Blowers work.
Air con in to Manual Mode - full cold - 65Deg

1) Turn right hand blower speed knob to full defrost - Hot air demist vent (so all good)
2) Some air out of the side vents (yes, all good)
3) No air out of centre vent (yes no air centre vent, yes all good)
4) No air foot well (Bad - some cold air was coming out foot wells)

Turn Fan speed to HIGH
Manual mode - full cold - fan speed high.

5) No air out of demist vent - (Bad full air out of demist vent)
6) Cold side vents - (bit of cold out of side vents)
7) Cold air out of centre vent - (next to nothing out of the centre vent)
8) Cold air out of foot vent - (all good here nice cold air out foot vent)

Manual mode - temp turned to full hot
Fan speed HIGH

9) no air demist - (1/2 Heat)
10) Hot air side vents - (yes hot air side vents - all good)
11) Hot air at foot vents - (hot air foot vents - all good)
Manual s

The solenoid to tun on the centre vent is behind the RH panel just infront of the console. at the driver left leg. Remove the vent from there and the panel slides forward and off.

Check the solenoid first IIRC it's the middle one. Make sure there is vacuum there and the solenoid is operating.

In the ECU there is a ZTX that drives the solenoids, mine was bad.

Mine is a 95 and am told I have the Mk3 as well with intermittent vent outlet issues as well.
By the way, your RH window switch is upside down on your center console. The left one is hidden behind your gear selector so can't see that one. Just noticed and curious.

This may help

Thanks Warren - those PDF's are great.
Removed the vent and panel, looks manky in there with lots of dried white powder...
I can see a solenoid, no idea if its the right one, can not pull it out to check as the vent is in the way, how easy is this to remove?
Has black vacuum hose so that should be the centre vent.

https://cimg9.ibsrv.net/gimg/www.jag...9772ec3852.jpg
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Yep that's them. The first one is the centre vent and the front one (front of the car) is the side vents. The hose you can see is the supply.

That vent screws on. I think it has 1 screw then it lifts up and pops out. The solenoids are on a steel bracket which is screwed in you can remove the bracket and solenoids then test them.

If it's any help, I had an issue where the centre vent vacuum solenoid wasn't working, so I simply removed it. The centre vent flap now slaps into position, rather than moving silently, but it does move. You can remove the Do Not Lift Here vent pipe to get better access.
https://cimg6.ibsrv.net/gimg/www.jag...0a0b93503b.jpg
Ordered the same part number, but it was a different colour. The old one was yellow. The XJ12 diagram on Jaguar Classic Parts is the accurate one, not the XJS diagram.
https://cimg7.ibsrv.net/gimg/www.jag...3d688dabc9.jpg
The new blue solenoid was too restrictive.
https://cimg8.ibsrv.net/gimg/www.jag...9a4a93f4bd.jpg
So I just bypassed it, connecting directly. One of these days I'll experiment with drilling a tiny hole through the old solenoid.

Thanks guys, great help with the description and pictures, makes life much simpler. I got the foot vent out, its tight in there.
How the hell did they design it like this so it all JUST fits.
The vacuum hose supplying both solenoids had come off, put it back on and lets see what we have.

Just got the car up to temp and so far it all works great.
Nice cold air blowing out the centre vent ... YEA.

Before I had full cold out of the demist vent, now it comes out the centre vent.

Can wait to drive it this weekend and test it out, now I just need to put it all back together...
Wires were real tight over the foot vent thing had to stretch them a bit, which is not cool, will be hard to put back in... might need a hammer.


Looking at the wiring there has been lots of lacking in there, but everything works.

This car used to be left hand drive, I think a lot was sorted out when it was converted to right hand drive.
I have a feeling this has some thing to do with why the switches are upside down.
Need to sort that some day.