I have bought a new ariel for my 1990 xj40 for a kenwood radio which was replaced by the previous owner instead of the original radio. But the ariel does not work, i cannot hear of a motor working and just wondering what the fault could be.

Could anyone please help me and point me in the right direction of what it might be, and if i need some parts if you can let me know where i should look at buying these parts from

 

For parts , you can contact ken@britishparts.com ,JagTechOhio .If those guys have don't have parts you can buy online from
www.jagbits.com , (a reliable source )

 

Hopefully this might point you towards sound. Without knowing how the previous owner wired in the radio 'tricky'.

If they used the Jag radio wiring then,

The aerial live feed is light green and black from the radio to the antenna logic processor.
From the logic processor to the aerial relays.
You will have White and black to the aerial up relay.
And red and black to the down relay.
Earth/ground is black.

So with your test light/meter see what you get at the aerial when you turn on the radio with the ignition on.

Check fuses, left box C2 and right box C1. and the aerial relays located in the boot/trunk, right side far back behind the panel.

If they didn't use the Jag wiring to connect the new radio then you don't have much of a choice.

Remove radio, to see how they wired it in and go from there.

If you want an insight into radio removal/replacement checkout a post I made in the General Tech Help forum on 08 22 2009.
From your previous thread that red wire could be anything, it certainly is not standard Jaguar. (I remember doing dumb things like that when I was a kid fitting extra spots or adding a radio, in order to get a quick live feed).