I recently bought a used 2005 RL (which I have been loving ) and have been replacing burnt out bulbs throughout the car. I thought the bulbs in the trunk were burnt out, however, when I replaced them, they still don’t light up. What do you think might be causing this? It is occurring with both lights within the trunk, which leads me to believe that the lights aren’t receiving the signal that the trunk is open. I looked all over to see if there is some kind of switch that is pushed when the trunk is closed and when the trunk is open the button is released, but couldn’t find it. Is this how the lights in the trunk know when to come on? If so, where is this switch? Or, do you think there is a deeper problem?

 

Possibly the fuse is out?

 

Is there a fuse just for the trunk lights? The other interior lights are working.

 

I know on my old TL I had to jiggle the trunk safety release (the latch that will open the trunk when you are locked inside of it) to get the light to work... try and see if that does anything

 

No luck. I wiggled the trunk safety release, but they still aren't coming on. Oh well, I guess I'll just have to do without the interior trunk lights.

 

I don't remember without checking but doesn't the mid show if the trunk is open and in gear? That would tell you if the status logic is working.

 

Good Idea!

 

db22 - Very good thinking!

To test the logic, I opened the trunk then drove in reverse, then in drive. Nothing showed on the mid indicating the trunk was open.

So there is definitely something wrong with whatever triggers the signal that the trunk is open.

So, now the question is, what initiates the logic that the trunk is open?

 

put your remote in the trunk and see if you can close the trunk. The trunk is not supposed to be able to close with the key fob in it, prevents you from locking your keys in there. If it allows it to close, definitely something wrong.

 

There should be a simple plunger type switch that gets compressed when trunk is closed. It might be stuck compressed thinking that trunk is always closed. Have never investigated on the RL, but have seen on many other cars.

 

That's kind of what I was thinking too. I did a little investigative work myself to no avail…yet. I don’t see any visible plunger type switch so I’ve taken apart some of the carpet that lines the trunk to see if I could see anything. Nothing there either, but I’ve only removed a small portion of the carpet. Hopefully I’ll find such a switch when I remove more of the lining.

 

Another excellent thought!

I put the remote in the trunk and closed the trunk...yep, it closed with no problem, so there is definitely something wrong.

Now I just need to figure out how to fix it.

 

You're right, no obvious switch. Must be tied into the latch directly or possibly position of the hinges.
A quick call to Service might be in order. They could tell you quickly where the switch is.

 

I figured it out!! I'll post pics a little later illustrating what was wrong. I had to take apart the trunk latch and fix part of it.

 

So here are a few pics of what I had to do to fix the issue. As it turns out, there is a mechanism that rotates when the trunk opens or closes. Attached to this mechanism is a plastic switch that rotates in a circular motion. Depending on the position of this circular switch, the trunk is considered "open" or "closed" as far as the interior trunks lights are concerned and the MID to notify that the trunk is open when in motion.

First I had to remove the plastic covering and then I had to remove the two bolts below in addition to one bolt not see in this picture.



Once the bolt were removed, I pulled the trunk latch out.


From there, I noticed the mechanism and that the plastic circular switch was not attached


I then attached the switch to the mechanism and then put everything back together and it now works!!


Anyway, thanks to everyone for your suggestions on helping diagnose and fix the problem!

While I’m posting pics, I thought I post one of the ride.

 

neuronbob,

Worthy of a Garage topic!