How do I replace the Tail light bulb in my 2005 Cadillac STS

Hello John Bland,

Light Emitting DIODES. DIODES... all semiconductors
are highly susceptible to FAILURE if improperly handled.

In a protected (anti-static) environment they do have an EXPECTED LIFE CYCLE.

In an UNPROTECTED... POORLY handled environ... you
can expect the slightest SPARK... (you might not even feel)
to render any/all semiconductors into USELESS trash.

STUDY UP: ESD = ELECTRO-Static Discharge.
Modern electronics should only be handled by qualified
technicians...

REAL "qualified" technicians (at least while the BOSS
is watching) wear anti-static wrist-bands.

$300 Compared to $10K, $20K and $60K (etc. etc.)
circuit boards YOUR STS tail lights are pretty cheap...

I'd still recommend borrowing, begging or buying
a WRIST STRAP ... I am just saying.
(see below (50 years industrial experience)).

http://www.rockauto.com/en/catalog/cadillac,2005,sts,4.6l+v8,1430942,body,tail+lamp+assembly,807

More Information for VARIOUS MFR GM2800199

Carnac the Magnificent

They come on with the light switch or daytime running lights. Some are just reflectors. If they aren't coming on, but tail lights do. You have either bad grounds, bad sockets, or bad bulbs.

You need to buy the entire tail light housing or if its the cyclops light in the center, you'll need to replace it as a whole part. You cannot replace individual leds on those parts.

http://www.carcarekiosk.com/video/2005_Cadillac_STS_4.6L_V8/lights/tail_light
video of how to change lamps

nowhere

It is much better to remove the trim from the inside of the trunk lid. It is quite easy and you will eliminate the possibility of scratching the paint on the exterior or breaking one of the lamp housings. With the trim off, you don't actually need to remove the lens. You can simply reach in, twist the bulb and remove. I've never had one of the lenses out (although I have replaced my licence plate bulbs) so I'm not sure if the ability to remove them from the outside is accurate or not. Also I take my replacement bulbs from here Aliexpress Homepage almost for free, hh
Hope this helped

ebay, guarantee your will find on there for 1/2 what a new one goes for

Just type in 05 sts tail light on Google and you will have 150 ads in front of you in seconds, from used to new, to cheap to taiwan. Check it out. Should be some on ebay.

you might have a bulb that is out, that you haven't changed or you've replaced with the wrong bulb or bulbs.

Bulb connected incorectly