I'm replacing the stock audio head unit in my 1994 XJS 4.0. I have figured out all of the wire connections from the original unit. There is one solid gray wire left in the original plug that I can't figure what it does. Any ideas?

 

From the wiring diagram I can't see grey (Would be "S" on a Jaguar schematic)

RK Red/Pink --> Locate Lighting
WU White/Blue --> Ignition 12V
P Purple --> Constant 12V

(then 8 speaker wires)

YG Yellow/Green --> Aerial

As I said, seems pretty simple and I can't see any grey wire in the diagram

 

I looked at the same diagram. I saw no "slate" either, and yet it is there in the radio's plug-in harness. Maybe it's an "out" for something like an amp. There is the multi-pin plug for the optional C/D changer, just not sure where this "slate" colored wire is going.

 

Can you identify to what pin in the radio connector this grey wire is connected to?

Also, can you possibly experiment with cutting off the grey wire while the radio's on to see (hear) if anything happens, or goes away? You can always connect it back, although if nothing happens there'd be no point.

I have replaced my stock radio and I don't remember a grey/slate wire and, of course, neither does the diagram show any such wire. Any possibility of something from the previous owner (if you didn't buy the car new?).

But, what are you doing with this replacement? Are you going to connect the stock speakers wires to the new radio, or are you adding an amp, in which case you'd be only using ignition, battery and ground wires, plus the antenna cable and nothing else from the stock set up (as you'll find no modern aftermarket Alpine radios that will talk to the stock CD changer.

Cheers,

 

I've already hooked it up, a Sony unit with Bluetooth for phone and music, 2 USB ports and a single CD slot. I replaced all 4 speakers with Alpine 6 1/2 inch 610's. Not adding an amp. I put the "blue/white" wire from the new Sony unit to the ant wire in the Jag and put a switch in the cubby to control the antenna if not using the tuner. I just taped the "slate" wire off. Have no clue what it does and it does not affect the functioning of the new unit. Here are some pics. Looks really good. I'm waiting on my ski slope to come back from Saul Chaplin with the cupholder mods.

 

I've added a picture of the switch I ran into the cubby to control the antenna. Really easy, just a 20mm hole through the plastic. Radio Shack switch for under $5.00

 

You might want to connect a a key lock switch and a push button switch up to the
"SECURITY Plug".
It is the plug with the Yellow and Black wire that is not attached to anything there under the
console.
It is also known as the "Valet" switch. Which is missing on the XJS.
You can use it to program the keyfobs back into the security system. Or add a new Keyfob.
I think you do have to go to the dealer to get a new key added to the car security.
True ?
I was thinking it was like the Corvette key that had this resistor thingie that was unique
to that car's security unit.
Some of the keys now have a RF ID embedded in the key that is read by the ignition
module... sort of like those RFID tags you find on merchandise in stores.

I am setting up a key lock switch along with the push button inside the console area.
I am using a key lock switch from one of my old PC's used to keep unauthorized users
from doing a reset or reprogram my key fobs. Takes a little bit of soldering.
Although I could use some crimp type of connectors which do not look nice.


The push button is easier to use when cycling the "Security" mode 5 times to put it into "Training" mode for the KeyFob recognition procedure.
Just turn the Security switch key to enable and then push the button switch 5 times and
there you go !

 

Hi, I know this is an old post but i have a question for drbill on the thread he started here. I sent an email but don't know if it got through so if anyone knows the answer, please help. Thanks, Bob.

Hi, You posted on the forum on 2015 about replacing your radio with a Sony stereo for your 1994 XJS. The link to the post is: https://www.jaguarforums.com/forum/x...-radio-140336/
I am getting ready to replace my system and speakers. I purchased a new power antenna to replace the old one that was not hooked up by previous owner. I also purchased a Valet button to install to help with the programming of the key fob. My 94 XJS did not have one of these but there is a rectangle hole it will fit into under the armrest. My question is what wires you hooked up to your Radio shack button. The button I have has 2 connectors and I have hooked up the purple (constant 12 volt power and the yellow/green (antenna wire but the antenna does not work. I tried reversing the wires and the antenna give a low click sound but did nothing. Did your antenna button have 2 or 3 wires? Are there any kind of relays for the antenna that you had to deal with to get the antenna to go up when you turn on the switch and then back down when you turn it off? I don't understand how the up and down is controlled. I figure the antenna would need power to retract the antenna once you flip the button to off position but there would not be any power to do that since the button turned it off. Any help would be appreciated. Thanks, Bob.

 

I sent you a PM...