48 49 Trunk Light Switch

[Michael Brittan CLC #2750]

I refer to the switch on the inside of the trunk lid which is supposed to activate when the trunk lid is opened.  Mine is not working.  I understand that these were mercury switches.  Is there a way to repair these switches once they no longer function?  Any advice would be much appreciated.  Mike

[Jack Mcilwraith]

Over time,the arcing when contact is made, carbons the mercury. Once it is totally black,it ceases to work. I have repared these items several times over the years. Between the bulb and the feed wire you will find a small "container". the mercury is in here. the contact can be pried out [carefully] and the mercury either cleaned with a contact spray through the hole where the contact had been. Or you could dump the old mercury and replace with fresh. I have used both methods. I can email a diagram if you wish. 

[Michael Brittan CLC #2750]

Many thanks Jack.  You experience with these switches is invaluable.  If you could email me the diagram, this would be appreciated.  Where does one buy mercury these days?

[Dave Leger CLC #19256]

Hi Mike,

  I have the same issue with my glovebox light (haven't tried the trunk light yet).  Working with mercury worried me, so I did some digging and found the modern equivalent is a tilt switch, which uses a metal ball inside.  I may try to adapt one of these where the mercury cylinder currently is:  http://www.newark.com/tilt .  Just another idea.

Dave