Hi Doug I have the Jag Lovers manual and need more specific data since I have a 1993 XJS coupe with the Delonair Mk iii but the manual is pretty short on actual testing etc as well as how to do fixes.

I have a scanner and would be glad to scan it to pdf and return it to you to post if that helps.

 

Hello Doug and Steve,

Many thanks for the help. I got the Mk iii operating manual and its very helpful. If you have anything else I will keep an eye out for it.

My problem is that the control unit seems to be working in part as when I increase the cooling temp to max at 65 degrees t he fan speeds up.

However, the flap to the defroster is stuck open and the flap to the center vents and side vents blows no air at all.

I had a problem with leaf build up under the front hood unit that lead to water flowing into the car just above the climate control unit. By the time I found the cause it had happened several times when washing the car but only after a delay of say 2 to 3 minutes while the tub filled up and then overflowed into the car.

I suspect that the activators have likely become corroded and jammed so that the flaps do not work when the control unit calls for closing the defroster and allow cool air to flow into the central vent and below.

In winter I get hot air only and can not turn down the heat. or mix more outside air with the heater air to cool it down. I suspect that the control is jammed or not operating properly .. that is the slide switch under the radio

I have a traditional muli meter so I can test things but I am not sure its digital. The readings are via a led type display not a manual clock like meter.

Thanks again. Any backpround on how to get into the area and fix the problem would be useful

mattaco

 

I have a question on the mark 3 system. Where does the micro switch in the fan speed knob get it's voltage from? I'm only reading .6V and it should be battery voltage minus one volt. Any help is appreciated.

 

Are you dealing with an XJS, or an XJ6 as in your signature??

 

Steve, Thanks for the manual. I passed it on to a friend who has an '87 XJS and he says "thanks". Any chance that you'd have something similar for a '96 4.0 Conv. If so I would be forever in your debt!

 

i have an xj6(xj40). It seems to be the same system besides the control panel.

 

See if this gets you what you need, Pete.

Cheers,

 

Many thanks.

It says "The ECM has been revised to accommodate
new functions and improve temperature stability
and consistency of settings"

Are the test points shown in the "Delanair MKIII Introduction" manual still valid or have the pin numbers changed with the new ECM?

 

Steve, I'll bet you're just the person to clarify something for us.......

At some point a Delanair Mark IV system was introduced. I've always thought it was for the XJ40 but I gather that later XJSs used it as well. It looks very similar to the Mark III system.

When the info you provided (above) started showing revisions circa 1993-94 I was expecting to see some mention of the Mark IV....but was disappointed.

Can you tell us which cars used the Mark IV system?


Cheers
DD

 

I wouldn't trust all the test point values for your later XJS. The '94 on systems have a control panel that is another module in it's own right, so the climate module [piano] is modified accordingly. Manuals such as the earlier one were no longer needed as the pinout voltages were incorporated in the Electrical Wiring Diagrams. Seek out the diagram for your XJS here on the Forum and you should be set.

Cheers,

 

The Mark IV system was specific to the sedans, the Mark III, with some updating, was used for the duration of the XJS. I think the references in the recent attachment are "'94 on". I believe the Mark IV was the only system that included humidity control [initially] and solar sensing. Mark III never had either.

Cheers,

 

Doug I've messaged you...last step before setting the car on fire!

 

Steve in France, Hi,
Please describe what "MEDIAFIRE" is. Sounds intresting.
I may still have a copy of a Delanaire II manual, also a Delanaire III.
I'll look for them.
I'm currently on the search of data for my 2004 XK8 VDP.
I have subscribed to alldatadiy.com but they are sort of sketchy on some of their info.

Jag Nut, PDX Oregon

 

Wow! Would ya LOOK at that!
Thanks for this, O compiler of great and needed information!

Now, my challenge is putting the info to right use!
I struggle with stuff like this 🤣

 

The pins that the manual instructs us to test … how do I locate and identify them?

 

Add me to the list. My '87 has the Mk III system (Pull for manual mode)
Need to get A/C and 'Hi' bower speed working. Thx

 

You can remove the "cheek panel" on the right side of the center console, and also the underscuttle panel below the right side of the dash (under the glove box on LHD cars) to get access to the MkIII ECM and it's pins. These photos are from my '87 SIII V12 with the MkIII system. The ECM has an extra set of pins that don't connect to anything, they are just there for testing purposes. I purchased some of these digikey products to place over the pins to prevent shorting when making contact with the multimeter probes. But I think I bought them from ebay for a lot cheaper than this. From memory, the pins are numbered 1-45 with 1 being the highest and 45 being the lowest/bottom.

https://www.digikey.com/en/products/...87175-3/352970

Before removing underscuttle panel


The silver testing pins are lined up vertically in the white plastic channel


stock photo of ECM removed from car.

 

Please add me to the list. I have a 1988 XJS with the MK III system.