1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Resurrecting failed LED brake light discussion

Discussion in 'Gen 2 Prius Main Forum' started by tnt01prius, Aug 10, 2023.

  1. tnt01prius

    tnt01prius Member

    Joined:
    Aug 11, 2007
    105
    18
    0
    Location:
    Surprise, AZ
    Vehicle:
    2005 Prius
    Model:
    N/A
    I haven't seen any threads lately on this aged subject. So I thought I would mention something I hadn't seen previously. I had replaced a cracked taillight assembly several years ago after the LED brake light failed. The TYC aftermarket assembly lasted about a year until it's LED brake light failed too. Well, I finally got around to taking some diagnostic steps mentioned in previous threads.

    In 'Ready' mode the voltage across the 12V battery read 14.18V and similarly at the incandescent taillight socket. All incandescent bulbs across the rear are functioning - don't recall having ever replaced any. Other side LED brake light has one weak light. There were no apparent loose connections. I swapped taillight assembly to other side, but nothing changed (why would it). Since the LED brake light receives reduced voltage (12V) via a circuit board, I snipped the wires feeding the failed LEDs and sent 12V directly from the battery, and the LEDs lit up perfectly. Then I pulled the circuit board from the bottom of the assembly, behind the protective foam, and what do you know, the problem found. Water had entered into the assembly and of course flowed to the very bottom where the circuit board sits. An unfortunate place for such a thing - I should think. See pics.

    I need a new circuit board, and of course try to eliminate water entering in likely via insufficient gasket on the TYC aftermarket assembly. Since the LEDs are good I'm going to attempt to contact TYC to get a circuit board replacement and new assembly-to-body foam gasket. Wish me luck.

    If that doesn't work, I'm going rogue with another inexpensive route for this 18 y/o car with very unnecessary LED brake lights (IMHO) that when they fail require the average owner to replace the whole damn assembly. Try doing that at a dealer. And people complain about replacing the incandescent bulbs - that's interesting.

    Please chime in with your thoughts. Would you suspect that most LED brake lights are not usually the problem, but corroded/failed circuit boards are the reason the lights go out?

    Anyway, thanks for reading.

    Circuit Board for LED Lights.jpg
     
  2. dolj

    dolj Senior Member

    Joined:
    May 14, 2012
    7,645
    3,858
    0
    Location:
    Wellington, New Zealand
    Vehicle:
    2007 Prius
    Model:
    N/A
    What about just replacing the failed light with a wrecker yard part. These go for many years without failing. I'd, of course, make sure the gasket was in good condition to provide a watertight seal. Water is the enemy.
     
  3. tnt01prius

    tnt01prius Member

    Joined:
    Aug 11, 2007
    105
    18
    0
    Location:
    Surprise, AZ
    Vehicle:
    2005 Prius
    Model:
    N/A
    dolj, that is a sensible option in some cases I have done. I was looking to buy a salvaged OEM TL on ebay, but I asked the seller for a closer examination of the TL assembly and he ended up telling me there is indication of water in one, another had a bug in it. Then he said I should just buy new. Ten years ago I would have been more comfortable with a salvage TL. However, 2004-2005 or even if a 2009 salvage TL would fit; at this point, due to age and weathering I would think it is just not worth messing with anymore. If somebody has a clean, dry, unblemished, fully functioning right side TL for sale I'm interested. Otherwise, I'm okay with other options. Thanks for your reply dolj.
     
  4. Brandon Luna

    Brandon Luna New Member

    Joined:
    Aug 11, 2023
    4
    1
    0
    Location:
    Vjančana, Lào
    Vehicle:
    2006 Prius
    Model:
    IV
    Ten years ago I would have been more comfortable with a salvage TL. However, 2004-2005 or even if a 2009 salvage TL would fit
     
  5. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
    9,075
    1,574
    0
    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    TYC is an aftermarket manufacturer of lighting so you have aftermarket tail lights on your car? I didn't think TYC was OEM supplier at least in '04 to '09? I have a bunch of these apart or at least did circuit boards and the wiring in the little LED light modules all snap out of the tail light assembly as obviously you've seen so I usually just move over the whole assembly just because I've only done it once and the circuit board my factory originals nothing like this had happened and when I'm built another tail light I set the circuit board on a piece of foam and wrapped it with zip tape which is that waterproof construction tape just to help with water mitigation and I keep the channels in my trunk that go behind the tail lights very clear and clean I'm actually pretty anal about that channel around the deck lid or the trunk gasket that it'd be kept very clean I live in the country with trees and woods so that area builds up very quickly and I keep it very clean so no water is allowed to get in the tail lights area I don't even think my factory rubber gaskets are there I reseal that with real Form in place gasket FIPG.
     
  6. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
    9,075
    1,574
    0
    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    Whenever I'm out and about that's one of the first things I grab off the car at least the tail light plastic lens and then the upper LED array and it's circuit board down at the bottom and leave the rest of the tail light just laying in the trunk of the car because I don't need the rest of the junk the fake chrome plastic pieces and all that sockets and holders I already have new as the old wore out from the halogen bulbs and regular light bulbs I replaced all the sockets and have LEDs and all the positions since I purchased the cars aftermarket tail lights are generally fine there's no issues with them The difference between up to 06 and after is before 06 has the blacked out upper LEDs with a piece of tent over them so you have to make sure you have both of the same tail lights or you have one with a tinted LED array and one without which may not bother a lot of people It will bother the h a l e out of me. And when you live in the southeast United States and you go to the junkyard even semi regularly you will see many many miles of Prius that you can pretty much get anything you want off of and the people at the counter don't even want to hear about it they don't really care about these cars they're more into Camaros big American iron and engines at LKQ when I walk up with tons of computer parts off of a Prius or Corolla or an Acura they like oh just give me $25 thank you have a good day I have a half a wheelbarrow full of these blue gray black green plastic boxes with huge plugs on them they have no interest in that mess and that's just how I like it.
     
  7. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
    9,075
    1,574
    0
    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    This is one big way the internet has fubar the whole car part purchasing hoopla now every idiot is online going oh yeah those parts are worth thousands and thousands of dollars and making all kinds of stupid claims every monkey at an Amoco transmission shop now has internet and all of a sudden half the cars they have outside for the last 15 years or all of a sudden small gold mines Right stupid is as stupid does.