How to change the license tag light bulb on 2005 Deville Cadillac?

google 2004 cadillac deville fuse box diagram for more info try it is free. took less than 5 second for answer

https://fuse-box.info/cadillac/cadillac-deville-2000-2005-fuses-and-relays

Here's a video showing you how to replace your back up light, Reverse Light Replacement 2000 2005 Cadillac DeVille 2001 Cadillac DeVille...

The fuse for the license plate light, if that is what you mean by tag light, is under the rear seat cushion On my 2005 deville it
is listed as the dimmer fuse. It is a 10 amp fuse. Look in your owners manual for its location.

Yep this answer is correct!! Remove the panel on the inside of the trunk, remove 8 10mm nuts, carefully pull of entire light assembly, and you will see the tag light bulb carrier. Turn it to the unlock position, and replace the peanut style bulbs, they just pull out of the socket.

To change the bulbs all you have to do is put a flat blade screw driver on the right side of the bulb housing and gently push to the left (towards the driver's side). This will release the catch holding it in and it will drop out and down on the end of its wiring connector. Twist the bulb counter clockwise to release it. Replace the bulb and just put the housing back into the opening left side first, then just push up on the right side till you hear a click.

you need the remove the lighting fixture first to access the bulbs.

this is straight out of the book ok

1. Open the rear compartment lid.
2. Remove the rear compartment lid trim.
3. Pull back on the rear compartment trim panel.
4. Unplug the lamp connector from the rear compartment lid wiring harness.
5. Press the grommet out of the rear compartment lid.
6. Remove the nuts retaining the lamp assembly to the rear compartment lid.
7. Remove the bulb.

remove your license and behind it you will find i think two screws then remove that panel and you should be able to get to it.

Remove license plate, remove screws and detach license plate pocket assembly. Rotate bulb holder, pull bulb straight out and replace.