Mercury switch trunk light spring

[gran coupe john]

Brown wire trunk light. Looking for a picture, or someone who knows this part. I heard it was spring loaded? I don't see the spring, if it is inside housing? If it is it is froze up, or rusted out. Can't figure this out, been on it for several days now.

 

[EW1BH27]

I took mine out of the car to check it out. That entire center thing moves up and down on mine and I can see the feed wire move the same amount. It's hard to tell if yours is stuck up or down. Here's a side by side picture of my #1003 bulb loose and locked in. You can see how much of the base is showing, that should give you an idea if which way yours is stuck since you're not getting that spring action.
PS: It would seem the spring is somewhere inside the black housing.

 

[gran coupe john]

Mine is loose, but the spring has freed up a little bit. Not enough though. Will continue to spray wd40 on it. Maybe, just Maybe it will spring up? That center piece was completely flat on the bottom. Has moved some.

 

[pschlosser]

If the spring below the bottom plate has rusted or gone bust, it may not spring back. You may still be able to get the bulb to function, even when this happens. But it takes some finesse. The problem may then be, any time you close the trunk lid, it jars the assembly and the bulb stops working.

WD-40 works, its a mixture of oil and water. The oil is much like kerosene and diesel fuel. If this were my assembly, I'd soak it for 20 minutes in warm diesel fuel, working the bottom plate up and down to dislodge any dirt or crud keeping the plate from moving freely. If I can get it freed, degrease and wash it with dish soap, rinse with hot tap water, and blow it out with a compressor.

 

[Xcudame]

I didn't post any pictures because there's nothing to add that wasn't in the first picture or EW1BH27's photos. But mine doesn't move very much like shown in EW1BH27's example. Since it started moving, just keep working it and it should free up! Probably hasn't been used for twenty plus years!

 

[gran coupe john]

It worked in 97, although it had some tape around it. That I believe to keep the bulb tight. The wire now is loose, and in compresses a little bit. Will keep working at it. Had the same issue with the dimmer switch. Now it works like new. Thanks guys I appreciate the information. Helped me figure out how the old mercury switch works.

 

[gran coupe john]

Is the brow wire 1003, or 1004 bulb? Have a 1004 bulb. I believe the spring is free.

 

[pschlosser]

Helped me figure out how the old mercury switch works.

It wasn't until last year I learned it even had a mercury switch. The bulb housing is so tiny.

I have speaker holes in my package shelf, but no speakers. At night, under hard acceleration or abrupt braking, I would see those speaker holes light up, indicating the trunk light was flashing on and off. For years, I thought the light worked through some grounding magic of the deck lid after it was raised. But once I learned about the mercury switch, I was like "Well, duh, that makes sense" seeing how it would light up with the deck lid closed, from time to time.

 

[Xcudame]

1003 for the trunk light! I just double checked the shop manual to be 100% sure.

 

[EW1BH27]

Is the brow wire 1003, or 1004 bulb? Have a 1004 bulb. I believe the spring is free.

My 1970 manual (black feed wire) lists a 1003 bulb. I can’t imagine ‘71 and up (brown feed wire) would use a different bulb. Maybe someone with a 71+ can check theirs.

 

[EW1BH27]

1003 for the trunk light! I just double checked the shop manual to be 100% sure.

What year, I was typing when you posted.

 

[gran coupe john]

71, a t1004 was in it, but loose. Will try to get 1003 and check to see what fits tight.

 

[gran coupe john]

It is a brown wire trunk switch, which there is a black wire trunk switch. Car is a 71, built 9/70. A t1004 bulb was in it. I put a 1004 in it, and fits like a glove. Will get new brake light harness tomorrow, to see if it works?? Thanks guys!!!

 

[Xcudame]

71 manual is what I looked at, but looks like John got a 1004 to fit! As long as it lights up, rock on I say!

 

[gran coupe john]

I am going to get 1003 tomorrow at advanced auto. They actually have them. Just in case the 1004 doesn't light up.

 

[Vaanth]

Is the brow wire 1003, or 1004 bulb? Have a 1004 bulb. I believe the spring is free.

Your trunk light uses a type 1003 bulb.

The 1003 bulb has a single contact base with the bayonet case serving as the other filament connection. The 1004 is a dual contact base connecting the filament. Note the single contact in the socket of the trunk light.

1003:





1004:

 

[gran coupe john]

That makes sense, there is only one contact at the base of the housing. 1004 fit nice, but would probably not work. Thanks Veanth

 

[pschlosser]

You can test the light outside the car, but you need 12 volts. A battery, a power supply, anything.

The battery minus ground hooks to the bracket, the battery plus to the brown wire, even down at the connector. Then tilt the baby.

I've used a digital meter continuity checker, too. if I recall correctly, one probe goes in to the back side of the connector, where friction holds the probe place. the other probe goes down in to the socket to the bottom center terminal... then tilt back and forth to test. Viola, we get tone. (my meter makes a beep tone when there is continuity.)

 

[gran coupe john]

Still got to get the 1003 bulb. Will try when I get it. Thanks can't wait