Trunk light switch?

Can someone tell me exactly where the trunk light switch is located, as mine seems intermittent ? Specifically Series 2 Coupe, but presumably they’re all the same.

Does it look like this? If so it is in the socket. Mercury switch.
If not it should be in the hinge or it’s different.

My Series III it was a regular pin switch on the right hinge. I know this because the one really wired electrical thing I’ve had with mine was that the trunk light was stuck on for a while. While trying to diagnose I had the switch Unwired at the bullet connectors and the light was still on. Curiously, when I tightened the slightly loose screws on the fixture itself, it went out and has worked correctly since. :thinking:

Couldn’t find any chafed wires.

A possible but not definitive test (because I don’t own a series two) would be to see if the light is only on with the side lights?

That’s the first thing I did on my 78 jag, disconnect that
trunk light.
I would never use it anyway.

Exactamundo, David - no wonder I couldn’t find the switch !

Having discovered that, it’s all fine; the thing is that the lid has to be almost fully open for it to work, and one of my hinges is poor, with the pivot holes having worn oval, so only when you actually hold it open fully will the light come on.

Next job therefore is to repair the hinge, or get another.

Many thanks for the help, everyone.



it’s part of the Jaguar magic, almost like gesture control - once you open the trunk in the dark and the light doesn’t come on immediately you just run your hand over the light unit behind the lock, barely touching it and - voilà - “let there be light!”.

The mercury switch works remarkably well, even after 40+ years. However, it likes being exercised. In case it starts getting lazy, go through a couple of open - close cycles.

Good luck


75 XJ6L 4.2 auto (UK spec)

I recently found this ‘replacement guide’ just in case it can’t be revived:

Given the characteristics of mercury I would have left that switch alone for sure … but the solution is surprisingly easy it seems. Thanks for preserving it on this site, David!


75 XJ6L 4.2 auto (UK spec)

You wonder how mercury can fail, but maybe it’s easy once it’s in a Jaguar !

I think the contacts the mercury touches can get corroded.

I think so. Even then it’s weird that it would being in a glass containment, but it is probably switching a bit much. Not my area of expertise.