Ok guys here is my questions.

The A/C in my 86 XJ6 has been working fine and the compressor was recently replaced. The settings all worked correctly , Low/ Automatic/ High. I got into it to drive it yesterday and the A/C will only blow on defrost. It does blow cold and strong out of the center vents. But does nothing on low/auto / high. Any ideas?

I have checked the fuses and they seem fine.

 

Two things come to mind.

Since "defrost" is the default mode of the system, which should default to "full fan, full heat, windscreen vents wide open", is sort of what you got going on.

1) The inline fuse behind the RH floor vent tin ducting may be blown. This will require the RH console cheek to be removed and look up where the handbrake would be on a RHD car, using your imagination. It is a pain in the rear to do on a RHD, but your LHD may be a snap.

2) The inline fuse in the earth wire of the a/c amp tucked in behind the radio, and accessable by removing the LH console cheek, may be blown., or that amp may have failed, they do after time, the internal relays die, and it is basically a sealed unit. Plenty of aftermarket units available from the usual Jaguar parts people.
The fact it was working OK until a sudden failure indicates to me an electrical issue.

 

I removed both covers on each side of the console and checked the fuses and they were fine. I'm not sure which fuse you are speaking of behind the radio? Its weird because when you put it on defrost the a/c compressor comes on and blows strong through the center vents and it is cold air.

Any more ideas? Can you give me more info on the fuse behind the radio?
Thanks,

 

OK, maybe my description is not the best, its an Auusie thing I suppose.

Behind the LH cheak you will see the relay "pack" for the fans, about the size of a packet of smokes. Good. Behind that in the depths that is basically behind the radio is the "amp unit" that drives the servo motors on the RH side of the unit, confused, good, so was I when I first went in there. In the general area of that relay box you will/should see a round plug with 9 (I think) wires in it. That is the plug and wiring for that amp, now in the black wire you will/should see an inline plastic fuse holder, that is the one to check.

JUST HAD A THOUGHT, SCARY I KNOW.

If that fuse, or that amp unit is failed the servo motors will NOT work. To check it quickly, switch the ignition ON, a/c knob on LOW, turn the temp knob, and LISTEN, so stereos, screaming kids, whatever TURNED OFF, you should hear the servo unit "whirring", as you change temp settings. If you do hear that, then that fuse and the amp is working, and that is NOT your issues, bugga.

Let us know the results so more diagnosis can be given.