LED's in the taillights

[hdrolling]

Decided to swap out all 6 bulbs in the tail lights for LED bulbs, x2 stop x2 turn x2 reverse

For the turns I installed Lasfit bulbs with built in resistors, but I knew from other posts that these wouldn't work in all the location at the same time.

So for the stop and reverse I uses VLED bulbs and external resistors for each light, no hyper flash or dash warning.

Plenty of room behind the light to mount the low profile VLED resistors.

I made a video but the turns were both already LED since I've been running them for a couple weeks already, in the video just the drivers side has the LED's installed just to show the difference.

I'll post some install pics in the morning.

 

[hdrolling]

For the turn signals I used the LASFIT 7440 bulbs, about $44 shipped on amazon. I installed these about two weeks ago and no hyper flash or dash warning that a lamp is out.

But front reading in different forums and facebook groups I knew that using this style bulb in all the locations would cause issues and one owner even contacted lasfit and they confirmed that they don't have bulbs designed yet to work all at once in the new '21 tahoe.

​

 

[hdrolling]

For the red brake light and white reverse I used the VLED 7440 red and white 921, the 921's are $ 80 for the pair and available in 5000k and 6000k. I ordered the 5000k.

The 7440 red were $70 for the pair, and for the four resisters (one per bulb) with the duo tap harness were $60.
The duo tap resister harness allows you to snap the harness over the wires without needed to cut or splice the light harness. You do need so pliers to snap them together over the wires.

Also the tap is for two wires and the factory harness uses three, you have to do some trial and error to see which two wires are the correct two. I did one bulb at a time. When I installed the bulb I turned on the Tahoe to make sure it worked, and then the warning would come on the dash for a bulb out. Then I would install the resistor to that bulb and recheck that the warning was gone.
That's how I verified that the wiring was correct, also you'll be able to feel the resister heating up.

Plenty of room to attach the resistors behind the lights, they do get hot so I would mount them to the car and not try to attach them to the back of the plastic taillight.
Tapping the wires for the resistors is the only time consuming part, mostly because I had to keep going to turn on the lights and verify that everything was working.

Doing it this way will run a little over $300

 

[hdrolling]

Here you can see the resistors mounted behind the tail lights, plenty of room and their not touching the taillights so they should have plenty of space to get air so they don't over heat.

 

[H1Chester]

After testing a bunch of different bulbs from Amazon, I finally found the ones (turn signal & backup bulbs) that don't give me an error code. Now, I still haven't found bulbs for tail/brake that don't give an error code. Has anyone found LED tail/brake bulbs with no error code? Here's the links for the blinker&backup bulbs I'm using:

Amazon.com

Amazon.com

Quoting a post from a different thread...

There are a few YouTube videos out there. Has anyone figured out a bulb solution yet for all the bulbs, without having to add resistors yet?

 

[hdrolling]

Quoting a post from a different thread...

There are a few YouTube videos out there. Has anyone figured out a bulb solution yet for all the bulbs, without having to add resistors yet?

None that I've seen, anyone that had tried pops a code or get hyper flash is they try to change all three lights (stop/turn/reverse). Mine is still going strong, never had a code or hyper flash yet.

 

[CASTLEDFW15]

I used pretty much the same set up with my 21 Premier. I used LASFIT 7440A for the turn signal…(Amber). I went with ALLA for the brake and reverse. ALLA has two versions for brake and backup…..one with strobe and one without. The strobe version illuminates a real quick three flash strobe as a “Attention Getter” then turns solid red or white.

I am planning the same idea for my 22 Z71…..same exact bulbs. I went back to OEM incandescent for trade in.

Where did you mount the resistors? My plan is a small metal plate 3X3” and mount between the frame and lens housing assembly. Velcro on the frame side where it is secure but NO drilling into the metal. If you want to go back to OEM just a small cut of the resistor wire, remove the Velcro and your done.

I have been experimenting for a few days and think I finally found the right size.

Simple summary, resistor, two small washers to use as spacers between resistor and metal plate……allows air to circulate around resistor to dissipate heat. Twin metal plates with a 1/4” 3X3” wood laminate in between. The wood provides a backing for the resistors to screw to. The other piece of metal plate on the frame side. Velcro on the frame and frame side of the metal plate…….stay with me.

The wood provides a surface for the resistor side of the mounting plate. The wood can also help absorb some of the resistor heat. The Velcro provides a pretty secure mounting surface for the mounting bracket WITHOUT drilling into the metal. If you want to go back to stock, then snip the resistor wires, remove the Velcro and no unsightly drill holes.

The resistors do get hot, yes momentary heat but still hot. The brake lights will be the major heat source.

One final step is some aluminum foil around the wiring looms and harnesses to prevent melting. Yeas maybe slight overkill but think like this.

Except for a bulb, lift gate actuator failure this area is one that would not be subject to routine inspection or maintenance. If task accomplished correctly and wiring protected , the lens assembly should only have to be removed for initial LED installation.

The other part is aside from the obvious bulb failure either by DIC message or physically looking at bulb…….if there is any wiring loom, harness or individual wires being melted it maybe too late.