THE INTERNATIONAL JAGUAR 'S'-TYPE REGISTER FORUM

Following up on the boot light issue, I decided to address the recalcitrant mercury switch. My car has been through at least two in 50 years. My solution was to replace the incandescent bulb with an LED (Moss part number LLB989NG {this is for a negative earth car}) and cut open the mercury switch, removed the plastic capsule, removed the end disc, empty out the two drops of mercury and replace with a small rolled section of lead sheet. This makes the switch always on when the side lights or headlamps are on but with the tiny draw of the LED I can not see this as an issue. The resulting improvement in boot illumination is far better than with the incandescent bulb. And while I was at it, I also replaced the map light bulb under the dash capping.

Yes the mercury switch is problematic, I hit the underside of the boot lid with my fist and it comes on. i do like the idea of an LED for this, Might source one and fit.

There is no boot light switch. A mercury switch operates it. When the lid is closed contact is broken. When it is open mercury makes the contact. Simple. You should just have replaced the Mercury.

Hi.
I know this is an old thread but it came in handy.
My boot light didn’t work, so I was looking for a switch working with the boot lid. Could not find any, the reason for that I found in this thread. Could not find it in the wiring diagram either, but I could see it was wired up to the number plate lights. So it can only work with lights on.
My old mercury switch wasn’t working. What I did was to wire in a general mercury switch lower in the boot lid behind a panel. Had to sit lower on a simple bracket twisted a little bit to get the right angle of the switch. Also wired in an inline small fuse for safety.
Obviously only works with light switch not in off position.
Harald.

Thank you all for the warm welcome and the valuable information. It really clarifies everything for me. It’s good to know there are others who know, care, and love this car as much as I do. And now a piece of cake.

He just told us about it in a post IIRC. Can't find it. From memory he opened it. Cleaned it up & inserted new mercury.


Found it:

"It's actually a tilt switch which are available on the market, but don't look like the original. A lot of times what happens is that the blob of mercury in the bulb holder gets corrosion on the surface of it and doesn't make the contact it should when the boot lid is opened and the switch is 'tilted'. I took my switch apart, not easy but possible, and replaced the mercury. A friend had a vile of the stuff and gave me a little blob. It too had some corrosion on the surface but if you take a tissue and dab at the mercury, the corrosion comes off on the tissue and the mercury becomes shiny again and is able to close the circuit. Mercury can be hazardous to your health and the environment, so be sure to wear rubber gloves and a respirator and properly dispose of any excess at your local hazardous waste facility." ~ Alan Wiedie.


Orlando's boot light wiring.


Colour Wiring Diagram:

http://www.jagstyperegister.com/images/ ... g-page.jpg

I have three mercury lights, one still in the car and two spares but none of them work. I know Alan repaired his but did he do a write up and explain how he repaired it. I cannot recall seeing a post. I might pull one of mine to pieces and do a post on trying to repair it.

Original. Alan Wiedie on this forum repaired his.

Hi Eddie first welcome to the forum and we will try and help you out.
The boot/trunk/ luggage compartment light should be in the top of the boot lid when you open the lid up. You will see a hole in the inner panel and a group of surrounding holes. The boot light was as you said a mercury light which when you had the side lights on there was a live feed going to it but if the boot lid was closed it was off. When you opened the boot lid the mercury was able to flow to the base of the light allowing the circuit to be closed and light came on. Over time the mercury can become dirty and the inner contacts corroded and the light stops working. You cannot buy a new mercury light. The wiring for the boot light comes in from the left side of the car and runs up the left hand boot hinge in to the double skinned boot lid. Very difficult to feed the wire back into place if it has been removed so if your car has been resprayed they possible did not bother trying to feed the wires through. The feed wire should be red which is the same colour of the side lights and I think I am right in saying there is a double rubber connector in the top left of the boot with the red wires, one of which will be for the rear side lights and the other connect should have a wire running to the boot light.
What you have suggested is what the previous owner of my car did. When the mercury switch stopped working he ran a new live wire from the fuse box to the boot. There is no permanent live wire already running to the boot so it has to be a new one. The wire connects to a small push switch mounted by the side of the original boot lights location in the boot lid with a standard light socket and bulb. I keep meaning to change mine to a modern 12v LED cluster which will be a lot lighter than a single bulb. When you open the boot the light is off until you push the button switch then the light comes on. You must remember to switch it off though or you will drain your battery. There might also be a timed light on the market you can buy so you switch it on but it times itself to turn off.

I’ve been unable to find the wire to use for the luggage compartment light. I’ve read the shop manual and all instructions are basically calling to use the trunk light as you do for the glove box light, meaning that it’s used only at night. In the shop manual it also talks about a light in the luggage lid. I cannot find the socket.
The operation calls for putting the headlight switch in S or in position for headlights. However, I want to use it any time the boot opens. For example when I open the trunk in my dark garage to look for something at night I want the luggage light to turn on. If I step out of the car at night and lock the car and then go to get something out of the trunk I want the light to come on.
I cannot find either a hot wire on the right inside hinge of the trunk lid or an old mercury switch that I read about in other Jaguar forums. The folks at SNG Barratt also see nothing regarding parts for a light or wiring for it.
My 1965 3.8s was painted before I owned it and maybe it was removed or disconnected. The bottom line is that there is no light and I want it to work like a modern car such that it turns on any time the luggage boot is opened (I think that is how the trunk lid is called). Do I have to run a new wire from the point where the fuses are? Is there a hot wire somewhere back there I anywhere near the back trunk to achieve this? If so then all I would need to do is add the new mercury switch or something like it.