Here is a nice little bedtime story (totally true, done by me):

- My better half drops me off at work, and as she is about to leave, I see her struggling. I come back to the car and she cannot put the shifter in drive. I show her the button next to the shifter, and explain that I don't have the time to figure it out right then and there, but it should work fine to get her home.
- As she is driving away, I see that stop lights are not working. OK, now I know why... (I call her on the cell phone and tell her to drive carefully to home and slow, and make sure she does not get rear-ended)
- I come home, go directly to O'Reilly and get a new brake pedal switch. $20.00.
- I replace the switch, and nothing.
- Now I am thinking "If it's the fuse, I will really be kicking myself...". So I replace the fuse. The brake light worked all of half a second, and then went out again. Hmmm...
- Just for kicks, I replace the fuse again (had a whole box of them). Again, it worked all of half a second, if that.
- So now, I know: there is a short somewhere. Hopefully it is not somewhere in the miles of wires in the car... or in that horrible place on the trunk hinge... Logic tells me that it is most likely in one of the light bulbs, plastic melted or something... but there are six such places in the stop lights: two on the trunk, two in the body , two in the middle (top of the shelf behind the rear seat).
- Which one is it? I start from all the way to the right. First one - nope. Second one - nothing. Check the two on the shelf in the middle - nope. Then I realize I connected the rear view camera to my left side stop light, must be that. I open it up, disconnect the camera - and nothing. Finally, it was the very last stop light bulb, all the way to the left. out of six possibilities, it was the sixth one that I checked.
- Disconnected that one, replaced the fuse again, and everything works fine. Found a fellow on craigslist who was anxious to get rid of his damaged stop light, and replaced that few days later.


Now I am thinking: if only all those were LEDs, such meltdown would be very unlikely. Anyone changed their stop lights for LEDs? I changed only the two on the third one, in the middle as they seem to go bad very frequently. If I replace other stop lights to LEDs, should I add resistors? note, I don't have a stop light warning, it's a 1990 LS400.

 

oh of course!!!! that's the way it goes! its ALWAYS the last one!! LMFAOOO!!!!!

 

Congratulations on your success to find the root cause.

I use LED lights after modifying the tail light failure sensor. My LED lights are kind of home made ones which are aimed to replace the regular bulbs. I just assembled those using 5 red LEDs for the industrial use. The white part is a metal board which dissipates heat more than plastic ones. The LED chips I used can pass through 200mA max but I dare limit the current 80mA. Because it's still brighter than the regular bulb. So the wattage is 12.6V X 0.08A = 1.008W and the heat is just limited.

Compared with a bulb which consumes 21W, my home made LED bulb unit needs less than 1/20th. You even can touch it by your fingers while turning ON.

 

glad it was not the trunk hinge harness which is most common on 1st gen cars.

i have all LED bulbs in my 97 as i have all clear tailights. i do not want to run load resistors so i have to live with the "brake lamp indicator" on. i have not experienced melting of the housings even with conventional bulbs.

there is a fix for folks wanting to run LED bulbs without running load resistors but is limited to only 2ng gen cars. i have not comfirmed that it works but it's authored from a well known member, and he was a master tech at toyota in japan! read:
https://www.clublexus.com/forums/ls-...cf20-21-a.html

edit: yamae is that well known member!

 

I'm not a master tech at Toyota but I know some about behind the scene.

 

You may not be one, but you sure know your stuff! Thanks for the info btw.
So, I imagine, I can just put in the LEDs and not worry about anything, especially since my LS has no brake light warning.

 

Funny thing is, I was thinking - "should I start from left or right?" Then I figured - what are the chances that it would be the very last one, so wherever I start, I will find it soon. Not.

 

So what exactly happened to cause the short? Did wire insulation melt or ?

 

i'm pretty sure all LS models have a no brake light warning light on the instrument cluster...

 

yes Timmy, I dont think so either

 

So what melted? Did the socket fall out? Did wires melt?

 

Mine does, and it drove me crazy to have that stupid light lit till I found out where the bad bulb was.

 

This worthless thread needs removal.

 

It was the actual contacts for the bulb - over the years the heat from the bulb slowly melted and bent things around the bulb and finally it created a short there. Could hardly see it from all the twisted plastic and everything being black... then I replaced just that - the wiring and bulb socket and it's been fine since then.

 

Thank you. At first I was thinking all the plastic melted that holds the bulb in the plastic lens assembly and then the whole unit fell out and touched something. So then its more like smeared solder at the contacts that shorted?