Well, Mercury is a metal, I think. So, as you say, would it evaporate if heated. The three stages of matter thing. Gaseous, liquid and solid?


Jaguar oddity: Went to market yesterday. Hmm. the power door and boot lock system came back to life. Don't have to get down and under and check the fuse in the auxiliary panel via the passenger side scuttle.


Working on daughter's ailing Passat. Fixing poor designed oil filler cap. The hard way as is my wont.


The coil pack arrived. Really nice assembly. Might well be the easiest part of the fix process. HA!!!
Carl
C

 

Jose,

Mercury may not evaporate, but maybe it corrodes? That is what looks like happened to the mercury in my '64 3.8S boot switch. I managed to pry off the end of the switch case and this is what I found inside. The key is a small plastic vial with a metal rod in the middle of it and a slug of mercury that makes the contact when the switch is at a certain angle (boot open). The metal rod makes contact with the end of the hot wire coming into the switch case and comes within 1/16" or so of a metal plate on the other end of the vial. This plate contacts the bulb end. Tilt the switch and the mercury rolls along the rod and bridges the gap to the plate - and there was light.

Not in my case, however. Instead of bright and shiny like I think mercury should be, mine is a dull grey. It is definitely touching both rod and plate, but there is no continuity. I'm contemplating removing the end plate from the vial and replacing the mercury. Anyone have any thoughts?

Alan

 

Yes, leave the mercury well alone! It's nasty stuff especially when heated.
If you really want a tilt switch buy a new sealed mercury (or non mercury) tilt switch and put it in a suitable place in series with a normal lamp.
If you want to keep the original switch for some reason then find a way of connecting the two contacts together, without heating or having removed any mercury contamination (i don't know how) and wire the new switch in series with that.

 

Alan, another option is to wire a XJ-6 Hinge Switch to either of the boot hinges and eliminate the mercury gizmo.

that is what I plan to do when mine fails.

I have a spare mercury switch from a 1964 3.8 S parts car but I have no idea if it is any good. Let me know how to test it. yes I have a voltmeter.

I have to say that is the best troubleshooting "study" I have seen for these mercury switches, only used in the S type as far as I know. (just like the S type Heater Servo, only used in the S type).

 

Jose,

Here is another pic of the plastic vial where I have removed the metal end plate. I filed the plastic down to where I could get a knife blade under the edge of the plate to flip it off. It sits in a recess in the edge of the plastic. When I put it back on, I plan to use superglue.

The way I tested mine was with a continuity tester. With the vial tilted so the mercury bridges the gap between the metal plate and the rod, you should have continuity and power to the bulb which is grounded through the metal switch body to the body of the car.

I'm trying to decide whether to put new mercury into the switch or wire a new tilt switch (readily available) in series with the power wire to the switch, after modifying the original switch to be always hot. This new tilt switch could be located behind the cardboard panel where all the backup and license plate wiring is. Then everything would look stock.

 

you have a 50/50 chance of success, so here's another option:

if you want to maintain that bulb socket / merury switch contraption for the sake of originality, why not bypass the mercury completely and jumper the two contacts, and add a hinge switch so that when you open the boot lid, the light comes on.

With the understanding that the boot light ONLY comes ON when the parking lights are ON, (same principle with the glovebox light), you could wire it the same way it is now, just adding a hinge switch which allows power when the boot lid is opened. And the good news? No messing with mercury.

 

Interesting. I've forgotten what was on, when I looked to see if my boot light worked. It did. But, it was day light. If I ever remember, I'll look in the dark. Why, I dunno? I have a flash light in there. Aka torch.


Decades ago, I swapped out the olds tech furnace thermometer control, aka Thermostat, in the house for a programmable unit. Kind of neat.


I kept the old one. A Mercury device. I hung it on my shop wall as a temperature guage. It must be level to function.


A local HVAC contractor collect the old mercury thermostats and busts them to collect the mercury. Why????


Mercury was useful in the "Gold Rush Days". A means of extracting gold from ore.


Old Mercury mines remain polluting big time.


Carl

 

Way back when in my former career, I investigated a refinery accident. Alleged injury by exposure to Mercury by one worker. Indeed, many tough chemicals involved. But, adequate protection afforded. Mercury not one of them.


But, this fellow did test out with elevated levels of Mercury in his system. SOG, he was an avid fisherman. Gee, the local fish have a lot of Mercury. Solved, declined....


Carl