I have searched the archives and read everything i can about this and none of the info or wiring diagrams and wire colours match what i have . I can figure out the wires for everything except the speakers , i know i need to connect a small amp for the bass speakers , thats no drama . I will attach some photos of what i have , and if anyone can help me with what colour wire goes where i’d be very thankful. I am fitting a pioneer headunit to the car.
Mark,
Which connectors are you showing in your photographs?
I’ve checked the circuit diagrams that I have for a 1990 XJ40 and I cannot match the wiring colors in your pictures to the ones shown in the circuit diagrams.for the six speakers identified in those diagrams.
Perhaps if I list the wiring colours I see in the circuit diagrams you can make some sense of them.
Rear bass speaker - Pink/red & Pink/orange
Left rear speaker - Red/brown & Red/green
Left front speaker - Red/green & Red/white
Right rear speaker - Red/brown & Red/green
[But .Those colours change to Pink/yellow & Pink/light green at connector before the radio]
Right front speaker - Red/green & Red/brown
[But…Those colours change to Pink/light green & Pink/white at connector before the radio]
Left bass speaker - Red/light green & Red/purple.
Good luck! 
Bryan , The connectors in the photos are , white ones are from the stock radio and the black ones are from the cars loom . As you can see the wire colours do not correspond to each other when plugged in , this is very confusing . I just need to know the speaker wire colours , i know the rest . Thanks for your reply. Mark
Mark,
That’s completely ‘thrown’ me. According to the circuit diagrams for a 1990 car, the connectors on the stock radio are both YELLOW - one a 3-way and the other a 15-way and there is not a WHITE connector anywhere in the radio wiring circuit.
However, on the 1991 models the main radio connector is a WHITE 14-way but the wire colours are exactly the same as those I quoted in my earlier post for a 1990 car.
However (again!) on the '93 models, also with a 14-way WHITE connector at the radio, the wiring colours for the speakers are totally different.
Could you have a radio from a later model year than the one for your 1990 car? What are the last six numbers in the VIN for your car?A 1990 model will be earlier than VIN 629286
Bryan , These cars are a real mystery , my connectors are 6 plug and 9 plug , the cars vin 626707 . The radio is Eurovox MCC 2461A , i’ve uploaded a pic. The radio is a new old stock one i bought some time ago , it works fine but i don’t have a good assortment of tapes , and my CD changer has gone south on me , so time to upgrade to something a bit more modern . Installing a new Pioneer unit , once i figure out the speaker wire colours.
Mark,
Well the car is certainly a '90 but I cannot find any “9 plug” connector in the circuitry for the radio on a '90 car (or for that matter on any earlier or later XJ40 radio system)
Is there any chance that the car was a ‘grey import’ from the Far East or Japan? I think the Japanese market models may have different wiring.
Unfortunately I don’t have any hardware to look at these days so I can only say what the published circuit diagrams reflect.
Bryan , Thanks for the replies , i don’t know if it was an import or not , i guess i’ll just take it to a good auto electrician for the stereo swap . It is one of those good ol Jaguar mysteries that just pops up now and again . Gotta love em . Thanks Mark .