Dear sirs!
Please help!

I have XJ12 S3 1985. Now i've got some troubles with A/C.
Temperature know is set to Minimum. Airflow is set to High.
Approx after 10 min of riding - airflow becomes very-very poor.
Switching between different modes (Low, Normal and High) do not help.
A/C working with max power only on Windshield mode.

Who knows - what reason?
Please help!

 

Hi Verisson,

This 'A/C' system is different.

There is no fan speed setting.

What we have is a climate control system.

The big difference is that this system gets the ambient temperature to what has been set and them maintains it.

So it may blow hard initially, but then backs off and basically adjusts itself in the background.

The most efficient settings are midway for temperature (75) and auto for mode

The slide at the bottom right on the ski slope only adjusts warmer / cooler air to the fascia panel

This system employed in the Series 3 XJ6 is an early type of climate control and so has its quaintness which takes a little time to get used to.

If your system goes quiet after 10 mins but still makes noise every so ofter as it adjusts itself, then I believe it is doing its job

Cheers,

Nigel

 

Dear Nigel! Thanks for your answer.
But one thing confuses me: what does mean Auto/Manual mode? What's difference?
In modern vehicles all's clear. But in this car - it's a puzzle

 

Hi Verisson,

That's Jag's for you!

The 'Hi' 'Low' Settings are manual overrides, however, the way the Delinaire Climate Control system works, the changes are incremental and minor compared to today's systems.

You have to remember that this system was pretty much the first of its' kind (Climate Control) when introduced in the late 70's.

Technology and expectations have moved / changed somewhat since.

And as the term implies, it is a climate control, not a fast temperature changer. (Think of an automatic system keeping your house at a constant temperature).

As I said earlier, to get the best out of it, leave the temp on 75 and the mode on Auto.

Cheers,

Nigel

 

And park in the shade on a warm day

 

By that you mean the temp dial is set for maximum cooling, yes? At that setting you should be getting nearly all the airflow thru the center dashboard vent.....unless the cabin temperature drops enough that the system brain decides that the cabin is cool enough (below 65ºF or so) that blended air (as opposed to maximum cooled air) will be sufficient . The system would then send air to the outboard dash vents and a small amount to the floor vents.





Selecting 'high' over rides automatic fan speed regulation. The fans should stay at high speed.







Can you be more specific?

You mean the volume of airflow drops drastically, yes?



So, the fan speed does not change between any of the three choices?



Obviously not right.

I suspect you have an amplifier problem.

Diagnosing a fault on this system can be very tricky and almost impossible without a 'known good" amplifier.

Do you have the shop manual? it has a fairly good troubleshooting guide. Better yet is the Delanair Mk II training manual, if you can find one

Cheers
DD



Who knows - what reason?
Please help![/QUOTE]