What is this Red/Yellow cable?

[Jeremy]

Help please.... I'm fitting new harnesses, and there's a red and yellow cable emerging at the dash centre from the engine bay harness that i can't find in the wiring diagram. On the old harness it wasn't connected to anything and connector had been taped over. Any suggestions? Many thanks.

[Heuer]

It is for the (optional) fog/spot lights which were never actual offered as an option by Jaguar. It would have connected to the four position light switch which later cars had.

[Jeremy]

Thanks David! Interesting. Odd that Jaguar went on incorporating it into the harness, when leaving it out would have saved a couple of pennies.

[andrewh]

When I wired my 3.8 it was not in my original loom so reckon it's there to streamline the new looms for cars with fogs. Proved very useful for me as I needed power through bonnet plug for daytime running lights and had this feed already bound in the loom

[ralphr1780]

It is for the (optional) fog/spot lights which were never actual offered as an option by Jaguar. It would have connected to the four position light switch which later cars had.

I am now replacing the 3 post switch with a 4 post one, for a quite interesting feature. On this 4 post the fog position activates fogs but cuts off headlamps, sidelights demain on... Will détail in a différent post.