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Technical => Electrical Tech => Topic started by: sarjxxx on June 20, 2010, 11:04:06 PM

Title: What makes the trunk light come on?
Post by: sarjxxx on June 20, 2010, 11:04:06 PM
Self Explanatory.

Is it a mercury/gravity switch in the bulb socket? Or is it something far more sinister?
Title: What makes the trunk light come on?
Post by: daminc on June 20, 2010, 11:07:06 PM
what makes you think it goes out.. lol
Title: What makes the trunk light come on?
Post by: hypostang on June 20, 2010, 11:15:52 PM
A smurf with a pull chain ?
Title: What makes the trunk light come on?
Post by: sarjxxx on June 20, 2010, 11:24:00 PM
:flip:
and
:flip:

lols

Just wondering cause I was considering an interesting mod back there and I was trying to figure out how to wire it up while keeping the auto-on feature. I figured its a mercury switch, but idk for sure if it might have something to do with a pressure switch in the trunk hinges or something else....

but...

I guess....

:whatever:!
Title: What makes the trunk light come on?
Post by: the_intimidator03 on June 20, 2010, 11:32:54 PM
sorry i dont have the information for you.. However you can follow the wire from the socket to the chassis and see if there is anything there.  If i could id go out and figure it out for you right now.  then agian i dont think mine works LOL
Title: What makes the trunk light come on?
Post by: Watchdevil on June 21, 2010, 12:10:18 AM
There is a mercury switch built into the bulb socket, just like most hood and trunk lights operate. When the lid is down the mercury flows into one end of the switch away from a set of internal contacts. When it is up, mercury flows to the opposite end of the switch and completes a circuit the contacts.  Mine is bad and I keep forgetting to look for one when I go to the parts yards...
Title: What makes the trunk light come on?
Post by: Watchdevil on June 21, 2010, 12:22:03 AM
Quote from: sarjxxx;326084
:flip:
and
:flip:

lols

Just wondering cause I was considering an interesting mod back there and I was trying to figure out how to wire it up while keeping the auto-on feature. I figured its a mercury switch, but idk for sure if it might have something to do with a pressure switch in the trunk hinges or something else....

but...

I guess....

:whatever:!


The switch is made into the socket in such a way that there is no direct access available to the single contact on the bottom of the bulb. 12V is contant to the positive wire. I believe the internal mercury switch closes the circuit for the 12V to the tip of the bulb base. The socket grounds itself through the metal bracket that secures it to the trunklid.


It might be easier just to supplement the trunk lamp with a second lamp and socket with no switch built in which will come on and off independently with the auto-lamp.
Title: What makes the trunk light come on?
Post by: the_intimidator03 on June 21, 2010, 04:24:21 AM
hmm do you know of other vehicles which also have these mercury switches?
Title: What makes the trunk light come on?
Post by: Watchdevil on June 21, 2010, 10:09:10 AM
Quote from: the_intimidator03;326108
hmm do you know of other vehicles which also have these mercury switches?


I am guessing that most any 80's Ford, Lincoln or Mercury sedan will have this same trunklamp if so equipped. I would go to a Pull-A-Part type yard and just examine a bunch of cars from various years and find one that will do the job.
Title: What makes the trunk light come on?
Post by: Scott D on June 21, 2010, 05:21:16 PM
Quote from: the_intimidator03;326108
hmm do you know of other vehicles which also have these mercury switches?


Would they cross reference with a Ford switch? :rollin:
Title: What makes the trunk light come on?
Post by: the_intimidator03 on June 21, 2010, 07:53:45 PM
LOL i meant mercury as in liquid metal LOL
Title: What makes the trunk light come on?
Post by: sarjxxx on June 22, 2010, 05:38:05 PM
Quote from: Watchdevil;326100
The switch is made into the socket in such a  way that there is no direct access available to the single contact on  the bottom of the bulb. 12V is contant to the positive wire. I believe  the internal mercury switch closes the circuit for the 12V to the tip of  the bulb base. The socket grounds itself through the metal bracket that  secures it to the trunklid.

thats what I thought...


Quote from: Watchdevil;326100
It might be easier just to supplement the trunk lamp with a second lamp  and socket with no switch built in which will come on and off  independently with the auto-lamp.

...and that's what I'm gonna be doing about it, only I'll completely  remove the stock lamp. Gonna be putting a set of super bright LED's in  there. Just like the ones under my hood.



Quote from: Scott D;326138
Would they cross reference with a Ford switch? :rollin:

lol, saw that coming!
Title: What makes the trunk light come on?
Post by: daminc on June 22, 2010, 06:06:04 PM
I think it stays on like a refrigerator light... lol
Title: What makes the trunk light come on?
Post by: sarjxxx on June 22, 2010, 06:36:55 PM
Quote from: daminc;326230
I think it stays on like a refrigerator light... lol

haha, mine really did used to...I had to fab it to not stay on! ...used to blow out every 2 weeks till I finally figured it out!