LED brake light replacement

Individual LEDs take about 3 Volts. It seems likely that Toyota put 3-4 in series (and then in groups in parallel), to use 12 Volts efficiently.

I would try to just replace the individual LEDs. They can be bought for pennies. Installing them in the assembly could be tough though.

 

i just got rid of an old MB diesel. you're gonna spend way more time and money keeping that old clunker road worthy, than getting ripped off for 1 tail light. i'd see if i could find one on ebay.
the diesel engine will run until the next century, but the car will rust away before your eyes...

 

Try autobeyours.com for used parts, in Indiana.

 

I broke one of my rear lights a short while ago and found many aftermarket units on Ebay (new) for around £50 UK. $80 US. but they were all the version with the smoked stop light section (pre 2006 and mine is 2008) so you should have no problem reducing the cost.

 

The LED stop light bulb assembly is sealed, hard to replace internal LEDs. You should be able to find a good used one for $50-$75. Try AdoptApart in Denver. Regarding the comment about struts on the Prius, the struts themselves are no more expensive than any other modern Japanese car...the rears are a little trickier to install because you have to remove the trunk trim panels and HV battery brackets, but that shouldn't add too much labor to the job, maybe 1 extra hour of labor for someone who has never done it.

 

Let's stop for a second and think about this. How likely is it that all 6 led's go bad at once? I would say extremely unlikely. The symptoms are, 1) it is dimmer than the other side and 2) it sometimes goes out completely. This indicates an electrical connection/wiring problem. Replacing the entire assy is not the next step. There is a good chance that replacing the entire assy will not fix the problem. I know you said you cleaned the connections but, now its time to check wiring. There is a reason its dimmer than the other side and, that's due to high resistance (aka bad connection). There is a reason it goes out completely (high resistance aka bad connection). The led's are the least likely cause of this problem.

In order to prove this, I would remove the assy and plug it into the other side and see what happens. If it works good over there, remove the left assy and plug it into the right and see if the symptoms are the same. I realize you won't be able to mount the lights on the wrong side and you may have to cut some wire ties.

The bottom line on this is 1) the led's are the least likely cause of the problem, 2) the symptoms clearly point to a loose connection, 3) replacing the assy will not likely fix the problem resulting in wasted money and time. Additionally, you'll still have the same problem.

 

The problem is that the LED's are I believe in chains of three in series with a current limiting resistor and if one led goes short circuit it can overload the other two burning those out. If a LED goes open circuit it turns off the supply to the other two LED's in the chain. The resistor itself can go high in value dimming all three LED's, but agree trying the unit on the supply from the other side of the car is a sensible first step.

 

I hear ya Brit but, even if this happens, you still have 3 other led's that should light up shouldn't you?

 

I've heard of the Prius LED stop light strip "burning out" before so that is most likely your problem. It should power on with 12V. I think there are a total of 12 LEDs in the strip and some circuitry. Best to remove the entire strip and test with a battery on the bench, then test the power connector on the car with a voltmeter or test light. I think you have to remove the black inside liftgate cover to access the connector.

 

We are talking about the brake lights in the units on either side of the car rather than the high center mounted unit. Unfortunately these are very difficult to repair effectively.

 

Paul,
Where is that located? That looks like the one on the hatch (3rd brakelight). The problem he's having is with the right side brake light(s).

 

Sorry, my bad. I recently had a customer with bad center light and was thinking of that while reading the thread. If LED problem is in the right or left taillight most likely water got in. Easiest way to fix is purchase a new (aftermarket) taillight on Ebay. They are good quality and only about $65-$80 delivered. You could try and take apart the light assembly and fix the LED circuit board, but you'll see it's not designed to come apart to be easily serviced.

 

Would water getting in the light cause these symptoms? I don't think it would.

I don't believe its a good idea to tell someone to spend money on something until we know the taillight assy is bad. Throwing money at it won't always fix it. Doesn't it make better sense to troubleshoot the problem b4 you replace something that hasn't been proven bad?

 

Yes, they should troubleshoot it first before ordering any parts...but based on my experience the only damaged taillight LEDs I've seen were because of water getting in to the circuit board area. If the OP finds another cause hopefully they'll share it here. I mentioned the cost of aftermarket parts to inform owners they have options other than the dealer...perhaps they are willing to spend ~$70 but not $250 to fix this issue.

 

Having just replaced a tail light unit on my Prius through breakage of the clear lens, I find it difficult to see how water could get into the light unit unless it was already cracked or broken.

Further any water would settle in the bottom of the unit and be clearly visible while the LED circuit board is in the top of the unit. Any water would have to enter from the cabin side of the unit giving rise to a flooded 12 v battery compartment or storage tray on the other side of the car.

My own light unit although the lower part of the clear lens was missing stayed dry and working through the wettest summer on record here in the UK. Pictures else ware on PC.

 

Thanks for the update. I'm glad you didn't spend a ton of money on a replacement assy.

If the mech "messed with the wiring", there is an exceptional chance that this problem will return. If/when it does return, try "messing with the wiring" (lol).

 

Tail light circuit board is under the foam seal on the back of the unit- can you get these?