Can anyone identify this wire?

[haffy]

Hi All, newbie here; first post so I hope I do this correctly. I just found a wire on my drive; figure it fell from my 1965 Etype Series 1 DHC. Short black wire folded in the middle with blue male connector and red female. Can anyone help me identify what it is so I can try to re-install it? I'd be very grateful as I'd like to solve it before I have to call the garage. I don't know if it is a clue but I had LED headlights installed and a while back the dip switch stopped working so they are currently stuck on full beam. I have been meaning to investigate and now wonder if this wire had worked loose before it dropped out.I figure that since it was on the drive it came from the engine bay rather than the enclosed wiring space behind the dash. Equally I may be talking rubbish:) Any thoughts gratefully received!

[Gfhug]

Haffy, welcome to the forum. Black wires are earth wires. The bullet end would go into a connector, sometimes a multiple connector, back into general earth circuit. The other female spade to the component. Difficult otherwise to be specific. As to it being original or new, who knows, sorry. There are many such connectors on the car, so not at all easy to say where it came from.
Maybe it came loose when the LEDs were added
Do you have the full maintenance manual with the relevant wiring diagrams? There are some in the knowledge section to help.
It could take a sparky quite a while to say where it’s from. But look for the circuit for the lights to see where the dip/main lights are connected and controlled.

BTW, please add your name and car type to your signature area by clicking on your user name top right. We can then respond appropriately for your car.

Geoff

[MSM]

I think it is fair to say that red crimp tags were not fitted by Jaguar when they originally built the car. It has been added necently(ish).

[40GT]

Along with the bullet connector which is also modern, process of elimination probably points to headlamp area, possibly a wire to a side lamp, why this would affect the beam I'm not sure.
You need to get digging really, earths first then live, although new work follows no rules regarding colour, so a black wire could mean anything.