No Brake Lights

LA1 · March 31, 2011

1992 LS400

Hello,

I've searched but haven't came up with a definate answer to my problem.

A couple months ago the bulb out light on the dash started coming on whenever stepping on the brakes but all of the brake lights were working fine. Yesterday, my wife came to pick me up from work, as my other vehicle is down, and I noticed that none of the brake lights were working except the top one in the back window. I should also mention that the taillights came on when I tried them but I forgot to try the hazards.

I bought new bulbs and installed them last night but no luck. Upon removal the top brake light on each side was shiny black but the filaments looked good; I left the new ones in. I then checked the fuse (25A) under the steering column. The fuse was good but I replaced it anyway, still no luck.

I inspected the wiring by the trunk hinge on the drivers side and everything looked good. I wiggled the wires with the brake pedal on to look for a short and couldn't get them to come on. I inspected the sockets for corrosion and nothing, they look very clean.

I am planning on getting a test light and starting from front to back but I thought I would inquire to see if there was a common problem I am missing. I also read in a post that the black box (forgive my ignorance I don't know the proper name) near the aforementioned hinge may need replacing. Is this the right direction?

I should also mention that it seemed to burn out brake lights quite frequently, probably once per year or so if I use good bulbs but if I use cheap bulbs they were going out more frequenlty. This includes both sides but the top left seemed to be the most common one to go out.

Any help would be appreciated. Thanks.

1990LS400 · April 1, 2011

Just curious -- did you unwrap the wires at the trunk hinge and inspect each one individually or wiggle the bundle? If the trunk hinge wires have never been fixed, it's just about impossible for the original ones on a gen 1 LS400 to last 19 years.

LA1 · April 1, 2011

No, I didn't unwrap them I just wiggled them around with the brake pedal down. Thanks for letting me know they break! I am not up on the LS's issues because I've never have to do anything beyond normal repairs and maintenance. I will unwrap them this weekend and have a good look.

Thanks again.

VBdenny · April 2, 2011

You are going to find they are wrapped up pretty good and it is a pain in the butt to get all the tape off the wires. Once you have them repaired, it is my suggestion not to try to force them back up into the original channel. I did that the first time then they broke again. I have left them just loosely attached and they have worked fine for years.

I always thought all the brake lights were on the same circuit so a wire somewhere is possibly broken and the trunk bundle is as good a place to start as any. Good luck with it.

LA1 · April 4, 2011

It is interesting you mention all of the brakes are on one circuit as I was going to ask about that. I found two broken wires, reconnected them and the lights in both sides of the center of the bumper work now but the ones on the outter ends are still not working. Looks like I will have to do some more wire inspecting when I get a chance but at least now I won't get pulled over or rear-ended.

Thanks again for the help guys, I always appreciate it!