Had no way of measuring temperatures on wires.

After a couple years with a LED tail bulb, insulation on the wire cracked and disintegrated along about 8 inches away from the bulb socket, exposing copper wire. The heat also melted the socket and mounting hole in the fixture.

 

I've never heard of this happening and have not seen this problem on my cars. But that's anecdotal going to test this later with a temperature gun.

 

Here's my test ran each bulb for 30 minutes and took readings. Power supply voltage at 12.1. All readings are the highest I could find except the socket took it from the same place in the middle. All readings are in Celsius.

LED bulb
Socket: 37.1°
Wires: 26.0°
Bulb: 86.2°

Incandescent bulb
Socket: 55.8°
Wires: 39.4°
Bulb: 246.0°

Higher current draw is the incandescent. I have LED bulbs that draw almost as much as the incandescent but does not maintain brightness they throttle after about 60 seconds.





Here are the bulbs


I couldn't duplicate your findings so whatever happened in your car was IMO very likely due to some other issue.

 

How did you measure the temps and what device you used?

In my car the tail/brake lights and license plat lights had LED bulbs installed. Wires to those LED bulbs had insulation brittle and crumpled from the socket out to about 8-12 inches.

The other bulbs with incandescent bulbs had no wire damage.

 

IR temperature probe. The LED bulb used 5x less power even if 100% of the heat generated went back into the wires (6 watts) that can't melt them.

 

Thank you for sharing your experience. I like to hear what people seen.

I had an led bulb fail in my home and it almost caused an electrical fire. Something inside the LED bulb- maybe LED driver circuitry I don't know, obviously shorted out and pulled high amps- I should've opened it up to see.

It was crispy charred so I don't use any Walmart LED bulbs in my house anymore- name brand only for now on for me cuz I really don't want a house fire.

Don't know if this can happen on automotive bulbs cuz I've never done a tear down on them or tried them.
I'm still running the stock incandescent and done no LED upgrades yet but when I do I'll be coming on here for recommendations.

 

Bad connection means a tiny part of the circuit gets very hot it doesn't require high current for this to happen. Easy to demonstrate run a 1.6 volt LED on 120 volts through a drop down resistor the resistor will get toasty and burn could even reach flash point and you get flame. Current draw will be less than 50 milliamps.

 

Hi Lex2k, yes you are correct and totally agree on that and seen heat damage many times working on circuit boards and controls from these very things so I can 2nd that.

Do they put any "driver circuitry" inside the base of the LED upgrades and do you feel they are safe if I want to upgrade mine?
Brands to stay away from?
From what I see in the pics members post it looks like a bulb with an led package retrofit so it must require some kind of circuitry and is this circuitry current limited or just simple current limiting resistors?

PS- like you say- current limiting resistors usually drift up in value and get hot until they open but driving circuitry if not done right and if that's what they use, I can see shorting thru a transistor and pull higher current. Just wondering.

 

Almost all LEDs are unreliable and even fire hazards. Automotive and home applications. Even name brands are not immune I had a Philips home bulb burn badly inside it started to smoke and then made a loud pop the driver circuit completely exploded.

There are drivers inside most automotive LEDs some are very simple some more sophisticated.

 

I have Canbus type Led bulbs in most of the rear lights on my 05 RX330, I have No Warning Lights on the dash, No Excessive current draw, No Heat or Wiring Issues, and Resistors are not Required with the Canbus type Led bulbs. They are Bright, Cool, Last Longer and draw Less current than Incandescent bulbs.
I used a Good Quality Canbus Type Led bulb, I learned a long time ago to stay away from Poor Quality Cheap parts.
Just My Opinion!

 

Which bulbs are you using exactly.

 

My 2005 RX330 has CANBUS, and I use Canbus type led bulbs in the tail lights, the tag lights and the backup lights. I still have incandescent bulbs in the brake lights, I'm not sure what led type they take, seems to be some confusion with what to use.
The turn signal bulbs also haven't been changed.
I don't remember the brand name of the bulbs, I bought them from a Toyota/Lexus parts reseller.