How do you change a rear tail light on a 2004 Cadillac cts?

Answer 1

Unfortunately I am finding that the Cadillac CTS has a sealed beam NEON unit as the high mount brake light and the whole fixture needs to be changed. The real bad news is the factory part can range from 200 to 400 dollars or more.

--The factory NEON unit can be converted to use LEDs with a little effort and less then $10 worth of parts. Once the NEON light assembly has been removed from the bezel assembly there are no more screws to remove for disassembly. DO NOT drill anything.

To open the sealed assembly take a utility knife and carefully cut the glue at the seams with the blade flush to the red lens. Once you have cut the glue to the best of your ability, soak the entire assembly in a bath tub full of very hot water to loosen the hot melt glue. Don't worry about getting water inside the assembly. You will not reuse any of the electronics with the exception of the power and ground feed wires which clip to the main bezel power harness. After the assembly has soaked for a little while take two wide flat head screwdrivers and gently pry the assembly apart working from the outside in like removing a bicycle tire from a rim. You may need to periodically soak the assembly to soften the glue. You should have both outsides open before trying to pull the center apart.

Once the assembly is apart remove the rusted out ballast and neon bulbs. Cut the feed wiring harness off as close to the ballast as possible. Replace the NEON bulb with LED Strip Red Lights (Flexible Waterproof 12V). I found a 96cm length for $6.50 which worked perfectly. I had to cut about 6 inches off. The wire side of the LEDs should go towards the drivers side. Tuck the excess length under the end clip on the right side reflector and cut the excess off leaving one extra LED at the end on the other side of the clip (which will not light). Solder the power feed harness to the LED strip making note of polarity (black wire is ground, white +) and insulate with either heat shrink or electrical tape. You may use a few small tie wraps or even twist ties to hold the LEDs against the reflectors.

I managed to do mine without doing any damage at all to the red lens or the black plastic base. Once I removed the glue I simply mated the two pieces and screwed it back to the bezel using only the compression of the attachment to the bezel to hold the whole thing together. Since the new electronics are water proof I didn't see the need to seal the whole thing with glue. You might want to drill a small hole where the ballast was for a condensation drain.

Attach the bezel assembly to the trunk and go get your state inspection!

Tools required: 10mm deep well socket, Torx 15 and 30 (star bolts), soldering iron and heat shrink (or electrical tape), utility knife, two fat blade flat head screwdrivers and most importantly a bathtub full of very hot water.

Materials: 96CM 48 LED Strip Red Lights Flexible Waterproof 12V, solder, small tie wraps.