How To Properly Install LED Taillight Bulbs

1. * Many if not most all cars have a system to detect a burned out bulb. It detects by applying a test voltage at a low current to the bulb. Typically battery through a 100kOhm resistor. Not enough current to turn a bulb on. The cold bulb filament acts as a very low impedance to ground so the applied trickle current's voltage is pulled essentially to ground. A voltage measurement system in the cars computer notices if this voltage got pulled low or not. If it didn't then the bulb is burned out and the computer reacts in some manner to annoy the driver.
   * PROBLEM 1: The led can only pull that test voltage down to about 3V because LEDs have a voltage drop that is effectively constant. That is not low enough to trigger the computer that the bulb is not burned out.
   * PROBLEM 2: The test voltage applies enough current to slightly turn on the LED. Yes even at 90 microamps an LED will glow. So owners go out into their dark garage at night and all the lights are glowing just barely. The amount of current is so low it has virtually no impact on the battery. But the owner freaks out and takes the car back to the dealer. "You sold me a car that glows in the dark and the battery is going to go dead!" The total test current if all the bulbs have been replaced with LEDs is less than 2mA so the battery is fine with that. Besides all the computer stuff(BCM, ECM,…) that keeps idling when the car is off draws as much as 50 to 100mA and will suck the battery dead in a month or two. So if you need to long term park at the airport then when you get back your battery will be dead. You need to install one of those battery quick disconnects. Or just open the hood and use a wrench to pull off the battery cable.
   * SOLUTION: Put a 2,700 ohm resistor in parallel with the LED assembly. For GM cars that is enough to pull the voltage close enough to ground that the computer will be happy. And it is enough to drop that test voltage to below the 3V threshold(about 0.3V) and stop the LED from glowing.
   * I tried to patent my 2.7kohm resistor idea. So far my patent has not gone through. (I mean really. I was trying to patent a resistor. But GM didn't think of it so shouldn't I get a reward for at least thinking of it?!) It was amazing to me that the car manufacturer had not explored using LEDs with their BCM and was just willy-nilly instructing us vendors to make our products with LEDs instead of bulbs. And they didn't want to tackle the project of changing the BCM for LEDs. I commented at the time that they should have a whole LED development project led by a VP of engineering coordinating with everyone. That was six years ago. I hope that they have modified their BCM by now. But I wouldn't bet on it.

2. Would it hurt anything to just let them flash fast? Simple curiosity.

3. Should had just used a electronic relay. I have all led from gtr lighting and a electronic relay from auto zone. No resistors. Works great. No hyper flashing.

4. I personally like the hyper flash it catchs attachion better than a slow flash do

5. The only "proper" way is to not install them at all… https://www.youtube.com/watch?v=2z5A-COlDPk&t=947s

6. I've got a ram, but all I did for mine was change the blinker relay that's rated for 4 led lights. Works the same.

7. scotch locks 😫

8. Sylvania Zevos are the best LED bulbs on the market
   made in europe not china

9. The turn signals I bought have built in resistors so they can be a direct replacement without any additional wiring and work great

10. My old 1963 Ford tractor was original with a 6 volt generator set up. Last year I converted to 12 volt alternator. Went ahead and changed all the light bulbs to LED. Brought it into the 21st century, and I can see much better with them

11. hi Eric, nice video, and great great comments , thank you to your viewers, im an old maintenance man , and was so fortunate to have been tutored by some very smart , common sense gents , your video was lacking in some areas , if you are showing and installation , please consider your hands may be in the way , and you might do a close up of the actual connection , per se, the resistor onto the wires, the viewers may be well versed on the use of tools and parts being used but there are also the neophytes, that want to learn from you, and by my tutoring , and training , please clean all surfaces when applying an adhesive, dust corrosion , oxidation , contribute to poor use of adhesives contact strength, maybe im talking to much , so i'll stop here, ciao 4 now

12. Heard you have to move. Quit paying rent and find an investor to partner up with. He puts up the money and credit and you make the payments and go 50/50 on the ownership. If you have the income and credit, do it alone.

13. I just install led on my 2007 ram dually and it work fine but then at night when i wanted to see the brightness one side of the running lights and roof lights where off. Only on one side was on. What could it be ? When i install them during day they did turn on.

14. Good to see you Eric and hope you and family are keeping safe and sound amidst this pandemic. As usual really appreciate the informative videos and please do keep them coming. All the best.

15. What's bad about fast flashing turn signals? Seems the fast flash is better for noticeing

16. I installed LED bulbs like that for my reverse lights. Although they look bright, they don't project as much light as you would think. I ended up switching back to the regular bulbs for the reverse lights and only using LEDs for the brake and turn signal

17. I replaced the OEM "filament" bulbs with the Sylvania Silverstar Ultra "filament" bulbs, and they were much brighter. Plus, unlike LED bulbs, they will generate some heat to help in snowyicy winter conditions. Also, to me, the LED taillight bulbs just don't look right. Also, I used Meguiar's PlastX polish, not a sponsor, and it really cleaned up and brought the shine back to my OEM housings.

18. LED flasher relay instead!

19. had 2015 truck led made the dash show light out and hyper flash relay fix both

20. Also in my experience with older GMs and LED turn signals, the hyper-flashing only happens when no other exterior light is on.

21. When I upgraded the taillights on my S10 Blazer, I changed the flasher relay from the original analog unit to a solid state digital relay. Solved the hyper flashing issue for me.

22. Just did my 94 Chevy with the info provided, turned out GREAT!

23. They make relays for $12.99 all over Amazon. They didn't have one for my 88 Suburban so I bought one and swapped shells. It took not even ten minutes. You could also do some spade pig tails. And this works regardless of the number of lights or amount of load.

24. Does your hazard mode still work?

25. Instead of those vampire connector clips, I would recommend Posi-tap connectors. They don't cut the wire strands like those do. Will never use those again.

26. The last thing I want to do is to drill holes into the body of my car and introduce water into my trunk or worse yet, start corrosion points. So, I used Gorilla Heavy Duty Double Sided Mounting Tape to attach the resistor to the car. the tape is phenomenal when it comes to handling heat, and when it adheres to something it's like 'crazy glue', it's been over a year and the resistors are still holding on. So, I agree with Eric on the way he attached the resistors. I would have used a different double-sided tape is all.

27. Ep50 is the part number for two prong led flasher

28. Hey do u still need an oem wing for your element we processed a element and going out tomorrow morning in the yard i need to know if u want it I can pull it b4

29. I put a electronic flasher instead of the stock thermal flasher on my Dodge. This way I can use led bulbs without modifying the harness at all.

30. Robert explains the need for resistors here

    https://youtu.be/V_Gla9smDa4

31. Nice upgrade looks good Eric came out amazing and super bright @EricTheCarGuy

32. Instead of Using red diod leds you can actually use white led diods since the housings are red will make them a ton brighter using white leds in red housings @EricTheCarGuy

33. I have had amazing results with Zevo Sylvania Led Bulbs from autozone have had all bulbs replaced in my 2000 4runner for last 8 years and zevo leds still going strong bought a whole set for my second 2000 4rummer I just bought 2 weeks ago @EricTheCarGuy

34. Don't need a resistor just replace the Blinker hazard relay and it will fix the hyper flash from the leds Eric oh wait this truck is to old to have a flasher relay if I remember correctly thats why you used the resistors @EricTheCarGuy

35. I always replace the blinker replay with a led relay before I install tail light and reverse and blinker bulbs in the rear nice work Eric @EricTheCarGuy

36. I recommend using the Error Free CAN BUS LED's that prevent hyperflash instead of using resistors for a few reasons:
    1. Resistors can be a fire hazard since they get so hot and/or damage plastic components such as housings or bumpers (of course this all depends on the installation location).
    2. There may not be enough room for resistors behind the housings.
    3. Resistors create 2 additional wiring connections and an extra component that can all be points of failure.
    4. As you mentioned, they may not be suitable for the electrical systems in newer cars.

37. What? Now I have to look at led taillights? The headlights are bad enough.

Comments are closed.