Trunk light staying on

[Stone pony]

First I added two led strips in the trunk. Tied into the orginal single blub and removed that bulb. I recently pulled the rear seat back down to let the a/c air get to trunk area to help keep something cool and noticed the trunk light are staying on. Is it possible that because I pulled the seat back down or some issue with the switch which I assume is in the trunk latch. Any ideas?

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[Cobra Jet]

First I added two led strips in the trunk. Tied into the orginal single blub and removed that bulb. I recently pulled the rear seat back down to let the a/c air get to trunk area to help keep something cool and noticed the trunk light are staying on. Is it possible that because I pulled the seat back down or some issue with the switch which I assume is in the trunk latch. Any ideas?

At the time you were peering into the trunk from the back seat access, did you perhaps have a door open? I believe the interior lighting is tied together, including trunk light.

I'm not aware of a separate rear seat access trigger that would illuminate the trunk area if just the seat back is opened from the interior.

Get inside the vehicle, close all doors and wait for the car to "time out" (everything turns off). Then open the back seat access and see if the trunk light is illuminated. If it is, then it's possible that lowering a rear seat back triggers the light OR you have to check your wiring for the LEDs you added. I know that in some instances in an older vehicle if replacing an incandescent bulb with LEDs, I recall there being articles or posts on the web that a resistor has to be added inline.

You can also test to see if it's your added LED strips. Disconnect your new LED strips, put the incandescent bulb back in and see how it functions. Then get a W5W LED bulb and put it in place of the incandescent and see if it functions the same as the incandescent. If both of those function the same, then the LED strips probably need a wiring modification.

2015-2019 S550's, the cargo bulb is an incandescent W5W bulb. 2020+ have LED.

W5W's can be purchased at any Auto Parts store or stores that carry replacement interior bulbs/LEDs.

 

[boB]

The trunk lamp (2019) is controlled by a "battery saver relay" in the BCM (+12 V) and a switch in the trunk release (GND), both have to be set for the lamp to come on. The BCM will shut off the power after a time (don't know how long), the trunk release switch should shut off ground whenever the trunk is closed.
If the "trunk ajar" indicator is not on then we can (usually) assume the trunk switch is off.

 

[Stone pony]

Thanks y'all...lights did finally go off. It seems the off delay time is different from that of the interior lights.

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