LED Headlights, Turn signals, switchbacks, brakes, etc Donald Trump may be Orange all the time, but why should you be?
Some of this information was copied from various forums, I would have linked it, but my concern was people being banned, etc with no access. Plus I wanted to edit a few things. It is not complete, I have NOT added the headlights yet.
LED Replacement Guide This guide covers all Trailblazer SS and "should" cover pretty much all of the GMT360 platform.
Interior Incomplete, I need to fix this
Exterior The wrong bulb in the wrong socket WILL blow fuses and cause unsafe or undesirable operation. There are two types of sockets used by GM, standard/normal and "CK". "CK" sockets are identifiable by having the GROUND on the SAME side of the socket. How to identify: http://www.youtube.com/watch?v=V8ONj-NJdjA
Reverse Lights: The reverse lights take a standard white (or whatever color you'd like) 3157 LED bulb. They are plug n' play.
Rear Turn Signal Lights: These take a RED 3157 LED bulb and require a 6ohm 50W resistor to prevent hyperflash. On the plug into the taillight assembly, the leftmost wire is negative and the second wire from the right is the positive for the signal. The resistor should be installed between these two wires, essentially creating a short.
A better solution is to get the LM486 flasher unit, (Please note, I did recommend the LM487 flasher, but I discovered it breaks cruise control, the LM486 works without a problem. It's a drop-in replacement for the existing flasher module, and still supports trailering. Best price is Amazon. You will NOT need resistors with this installed. https://www.amazon.com/2002-2009-Envoy-Signal-Flasher-LM486/dp/B00KQV1K02/ref=sr_1_2?ie=UTF8&qid=1546903183&sr=8-2&keywords=LM486 *The module installs in the horizontal drop-plate under the dash, right above your feet, should be a gray plug on the left side after you remove the plate.
Brake Lights: The brake lights require a RED 3157 LED for a CK socket. Failure to use a CK bulb WILL blow your rear parking light fuses or your brake light fuse located under the rear seat. As long as you have a CK bulb, they are plug n' play.
Front Turn Signals (under the headlight): These require an AMBER 3757A LED for a CK socket. Failure to use a CK bulb WILL blow the front parking light fuse located under the rear seat. Just like the rear, these bulbs require a 6ohm 50W resistor between the negative and turn signal positive to prevent hyperflash. Optionally, you can get AMBER/WHITE 3757A SWITCHBACK LEDs for a CK socket. These bulbs are white for the parking lights and amber for the turn signals. Here is a demo install: http://www.youtube.com/watch?v=I5NOi_-dNmI
Front Side Turn Signals (beside the headlight): They take an AMBER T10/194 LED (you can also get a tiny "switchback" for this socket too: http://www.youtube.com/watch?v=OpDMdxJBRHA ) You do not need a resistor for this bulb (mine has blown before and I didn't get hyperflash).
*IF you choose to use resistors, be sure to mount the resistors to metal, they will get VERY HOT!
Common Questions: Q: My LED bulb won't light up?! A: Flip the bulb 180° and it should work.
Q: My parking lights aren't working in the front/rear?! A: You have installed a standard LED bulb in a CK socket and blew a fuse. Make sure you are using CK bulbs in the CK sockets and replace the fuses (located under the rear seat).
Q: Only my 3rd brake light is working?! A: Similar to above, you blew the stop light fuse by using a normal LED bulb in a CK socket.
Q: My turn signals don't hyperflash with the 4-ways but do hyperflash with just the left/right? A: You forgot the resistors or need the Novita flasher linked above. You need 4x 6ohm resistors to get the required resistance.
Q: How do I get the dome/map light lens off? It feels like I will break it. A: The rear of the lens snaps down, there is a tab in the front anchoring the lens to the ceiling. Pull on the lens from the back.